(the ancient *Leontini*), a town of Sicily, indendency of Syracuse, on the River Porcari, 20 miles N.W. of Syracuse. It was founded in the first year of the thirteenth Olympiad, by a colony of Chalcidians, and, when taken by Marcellus, was one of the chief places in Sicily. It retained its importance till the earthquake of 1693, by which it was completely ruined. The neighbourhood is productive, but unhealthy. The inhabitants are chiefly engaged in fishing on the neighbouring lake of the same name. Pop. about 5000.

LEO I., Flavius, surnamed the Great, and the Thracian, was born about A.D. 400, in the country of the Bessi, in Thrace. On the death of the Emperor Marcianus, in 457, being then only a military tribune, he was recommended by the patrician Aspar to the soldiers, who proclaimed him emperor. His election was ratified by the senate, and he was crowned by Anatolius, Patriarch of Constantinople, thus introducing the custom, which afterwards became so prevalent, of Christian princes receiving their crowns from the Leo III., hands of bishops. No sooner had Leo ascended the throne, than he resisted the influence which Aspar sought to exercise over him, by telling him that "it was unbecoming for a prince to resign his own judgment and the public interest to the will of a subject." In 466 the Huns, invading Dacia, were defeated by his generals, Anthemius and Anastasius, with the loss of their chief, Dengizce, son of Attila. In 468 Leo, in concert with Anthemius, now Emperor of the West, equipped a large naval armament against the Vandals of Africa, who, under their king, Genseric, had long been the scourge of Italy and the Mediterranean. His fleet, consisting of 1113 ships, having each 100 men on board, was intrusted to the command of his brother-in-law, Basiliscus, who, after a prosperous passage, disembarked his troops safely at Cape Bona, about 40 miles from Carthage, the capital of the enemy. Genseric, feigning a desire to submit, requested and obtained from Basiliscus, a truce of five days. During that interval, favoured by the wind and the darkness of night, the fleet of Genseric, with several fire-ships in tow, attacked the Roman vessels, burnt and sunk one-half of them, and thus caused the entire failure of the expedition. A public opinion that Aspar had in some way effected this disastrous defeat, afforded Leo a pretext of getting rid of this dangerous king-maker. Taking advantage of a burst of public odium against Aspar, he ordered him, and one of his sons, to be put to death, and thus left a foul stain upon his own memory.

Under pretext of revenging this murder, the Goths invaded Thrace, and, though overpowered after two years, disturbed the last days of Leo. He died in 474, leaving the crown to Leo, the infant son of his daughter, Ariadne. Though scarcely deserving of his surname, the Great, Leo was active, enlightened, and prudent; and though illiterate himself, was a liberal patron of learned men.

Leo III., Flavius, surnamed the Isaurian, Emperor of Constantinople, was born in Isauria, and was originally called Coson. His father, a wealthy grazier, emigrated from Asia Minor to Thrace, and obtained for his son the rank of a spatharius in the army of Justinian II., where his eminent abilities soon excited the jealousy of the emperor. From Anastasius II. he received the command of the troops in Asia; and when that emperor was deposed in 716 by Theodosius III., Leo, marching to Constantinople, compelled the usurper to resign, and the vacant crown was conferred upon himself, by the suffrages of the soldiers, in March 718. Soon after his accession, the Arabs, in large hordes, invested Constantinople so closely by land and sea, that the final capture of the city was considered certain. The Emperor, however, sailing out of the Golden Horn with his galleys, burnt some of the hostile vessels by means of his fire-ships, and threw the rest into confusion. After sustaining severe losses, in two other naval engagements and in one land battle, the Arabs in 720 were obliged to raise a siege which had lasted two years. Meanwhile, the deposed Emperor Anastasius II., expecting the downfall of Leo, had formed a treasonable conspiracy which was discovered in 721, and punished capitally. Shortly before this period the dislike entertained by the Mohammedans and Jews against image-worship had gradually spread among the Eastern Christians, and had originated the sect of the Iconoclasts, or image-breakers. Adopting the views of this sect, Leo issued a general edict commanding the removal of images from all the churches of the empire. His chief object was to reform the church; but he also undoubtedly aimed at drawing the Jews and Mohammedans within the pale of Christianity, and thus increasing the strength and splendour of the empire of the East. This edict met with general opposition. Instigated by Pope Gregory II., the Italians refused to obey, and when Paulus, exarch of Ravenna, was ordered to employ force, resisted, and repulsed him. Peloponnesus and the Cyclades rebelling, sent a fleet to invest Constantinople, but were worsted in a sea engagement, and compelled to submit. In Leo V., Constantinople, also, an insurrection arose, which, after causing much bloodshed, was quelled by the capital punishment of the ring-leaders, and the deposition of the Patriarch Germanus. In 731 a council held at Rome by Gregory III., condemned the Iconoclasts; and incited in Italy so much opposition to Leo, that he sent a powerful armament against that country. The armament failed, and Ravenna and the exarchate were seized by the Lombards. Leo in revenge transferred, in 734, Greece, Macedonia, and Illyria from the patriarchate of Rome to that of Constantinople, an act which eventually caused the schism between the Greek and Roman churches. The remainder of his life was disquieted by a protracted war with the Arabs. He died of dropsy in 741.

Leo's character, much depreciated by the advocates of image-worship, is best elucidated by the facts of his life. His rapid rise from obscurity to the pinnacle of power, his firm and successful administration, amid foreign assaults and domestic plots, and his resolute prosecution of the reformation of the church, all indicate a wise and provident policy, great vigour, and decision of will. His early military life, although it rendered him cruel and obstinate, did not taint the purity of his manners.

Leo V., Flavius, surnamed the Armenian, was of Armenian descent, and son of Bardas Patricius. Serving as a general under Nicephorus I., he was banished for treachery, but in 811 was recalled, and appointed dux Orientis by the succeeding emperor, Michael I. This favour was repaid with ingratitude; for Leo, after gaining some reputation in his wars with the Arabs, accompanied his sovereign, in 813, on an expedition against Crum, King of the Bulgarians, and taking advantage of the disaffection of the army during a battle with the enemy near Adrianople, withdrew with the forces under his command, and left Michael to total defeat. Having thus stripped the emperor both of power and reputation, Leo was called upon by his army to mount the throne; and when he pretended to hesitate, his friend, Michael the Stammerer, confronted him with his naked sword, exclaiming, "With this sword will I open the gates of Constantinople, or plunge it into thy heart, if thou refusest any longer to comply with the just wishes of thy comrades." Leo marched into Constantinople, and was crowned in 813, without any opposition. In 814 the Bulgarians, threatening the capital, were defeated at Mesembria; and, in the following year, Leo again repulsing them, invaded their territory, and effectually subdued them. In the peace that ensued, all his efforts were exerted to effect the equal administration of justice, and the suppression of image-worship; but his punishment of the latter offence was so severe and unrelenting, that even his best friend, Michael the Stammerer, became his enemy. Having organized a conspiracy, Michael was betrayed, tried, and condemned to be burnt. On Christmas Eve he was dragged to the place of execution; but when about to meet his fate, was remanded to prison at the entreaty of the empress, who was unwilling that the sacred season should be profaned by such a horrible death. During the night, his friends having formed a plot, appeared at the palace chapel on the ensuing morning, in the garb of priests, and while the emperor, as was his custom, began the chant, they fell upon him, and in spite of his desperate defence with the large cross, murdered him, A.D. 820. He was succeeded by Michael the Stammerer. Unlettered, and ignorant of the laws of government, Leo erred in introducing into his civil administration the severe and condign punishment of military discipline.

Leo of Byzantium, an historian of the time of Philip, and probably of Alexander, occupied an important office in the Byzantine commonwealth, during its invasion by Philip. According to Hesychius of Miletus, he was general of the forces. During the siege of his native city, or shortly after it, he was sent on an embassy to Athens. Byzantium, when on the eve of being captured, was succoured by the Athenian auxiliaries under Charos, n.c. 340, and afterwards under Phocion, and Philip was compelled to withdraw. After this repulse, the king, according to Suidas, accused Leo to his fellow-countrymen of having designed to betray the city for money; and Leo, afraid of falling a victim to popular fury, hanged himself. Hesychius of Miletus, however, states that he died during the siege, before the arrival of the Athenians under Charos. On both of these statements considerable doubt is thrown by Suidas and Eudocia representing Leo as the author of two works,—Τὰ κατὰ Φιλίππου καὶ τὸ Βυζάντιον (The affairs of Philip and the Byzantines); and Τὰ κατὰ Ἀλεξάνδρου (The Exploits of Alexander). The other works commonly attributed to him are,—Τετραπληγικόν (Tetraplemicum); Περὶ Βασιλέως or Βασιλεῶς (De Basilo or Beso); Ὁ τῆς ἐκκλησίας (The Sacred War); and Ἐπιστολαῖς (De Seditionibus, or De Statibus). None of his works are extant.

Leo Diaconus, or the Deacon, an historian of the tenth century, was born at Caloi, a town of Asia Minor, probably about A.D. 950. From his history we learn that he was studying at Constantinople in 965; that he was in Asia in 973 or 974, when Basilus I., Patriarch of Constantinople was deposed, and that in 981 he accompanied the Emperor Basilus II. on his expedition against the Bulgarians. We infer also, from some of the events he mentions, that he must have lived at least till 993. His works are,—Ἰστορία, Oratio ad Basilium Imperatorem, and Homilia in Michaelem Archangelum.

Of these, the two last exist only in manuscript. His History was first published at the expense of Count Nicolas Romanoff, Chancellor of Russia, accompanied with a preface, a Latin version, notes, and engravings from ancient gems, by C. B. Hase, Paris, 1818. This edition, without the engravings, was reprinted in the Bonn edition of the Corpus Historiae Byzantinae, 1828.

Leo Grammaticus, a Byzantine historian of the tenth century, is said to have been governor of Cibyra under Constantine VII. His work, entitled Χρονογραφία τῆς Ῥωμαϊκῆς Βασιλείας τῶν προγενέστερον (A Chronography, comprising the Acts of the more recent Emperors), is a continuation of Byzantine history from the accession of Leo V., the Armenian, A.D. 813, to the death of Romanus I. in 948. Published along with Theophanes, under the superintendence of Combes, Paris, 1655, in the Parisian edition of the Corpus Historiae Byzantinae, it was reprinted at Venice, 1729. Leo probably wrote his History in the time of Romanus II.

Leo of Thessalonica, surnamed the Philosopher, a learned ecclesiastic of the ninth century. The date and place of his birth are unknown. He studied grammar and poetry at Constantinople, and arithmetic, rhetoric, and philosophy in the island of Andros, under Michael Psellus. By exploring all the monastic libraries in continental Greece, and perusing their valuable contents, he amassed a large stock of general information, and, returning to Constantinople, became a teacher. One of his pupils having been captured in war by the Moslems, and becoming known through his geometrical acquirements to the caliph, who was a patron of learning, extolled the attainments of his master Leo so highly that he was despatched with a letter to the Philosopher inviting him to Baghdad. Afraid to correspond with an enemy, Leo contrived that the letter should be laid before the Emperor Theophilus, and was thus recommended to royal patronage. The emperor appointed him public teacher or professor, and afterwards ordered the Patriarch Joannes, the celebrated Iconoclast, and a kinsman of Leo's, to consecrate him Bishop of Thessalonica. On the death of the emperor, and the instalment of his widow Theodora in the regency, he was deposed from his see for his iconoclastic opinions, but was afterwards appointed to the management of a mathematical school, established in Constantinople by the Caesar Bardas. The latest period of Leo's life of which we have any notice is 869. The date of his death is unknown.

The only extant works that can with any probability be ascribed to Leo the Philosopher are several astrological MSS. existing in various European libraries.

Leo X., Pope, the second son of Lorenzo de Medici, was born at Florence in December 1475. His original name was Giovanni or John. Having taken the tonsure at the early age of seven, he was presented with two rich abbeys, through the influence of his father with Louis XI. of France, and Pope Sixtus IV. Many other benefices followed; and, in 1488, when only thirteen, he was raised to the rank of cardinal by Innocent VIII. Hitherto he had been under the tuition of Chalcondylas, the famous Greek historian, and Angelo Poliziano; and, being naturally sedate even in his youth, he had evinced that love of classical learning for which he was afterwards so noted. He was now sent to Pisa to study theology, and, on his return in 1492, was invested with the purple; and soon afterwards went to reside in Rome as a member of the sacred college. On the accession of Pope Alexander VI., whose election he had opposed, he returned to Florence, and remained there until the invasion of Italy by Charles VIII. of France obliged his family to flee in 1494. Repairing to Bologna, he afterwards, in 1499, travelled through France and Germany, enjoying the society of learned men, and indulging his love of literature and the liberal arts. Returning to Rome, he lived in strict seclusion until the accession of Julius II. in 1503. Having recommended himself to the pope by his activity in public affairs, he was appointed governor of Perugia; and, in 1511, for his fidelity in this administration, he was rewarded with the high office of commander of the papal forces in the holy league against France. At the battle of Ravenna, in 1512, he was taken prisoner and conveyed to Milan, but, recovering his liberty soon afterwards, he returned to Bologna, where he governed the district as papal legate.

The death of Julius II., in 1513, recalled him to Rome, and in March of the same year he was elected his successor in the pontificate, and assumed the title of Leo X. No sooner was he seated in the papal chair, than the invasion of the north of Italy, by the French troops of Louis XII., summoned him to exercise his talent in the field. Mainly by means of Swiss auxiliaries the French were defeated at Novara, and Louis XII. was forced to seek absolution from the papal power. The peace that followed was spent by Leo in patronizing learning and the fine arts. Not long after his accession he had appointed Bembo and Sadoleto papal secretaries. He revived the Roman University by means of rich presents and valuable endowments, and by attracting to it eminent professors from different lands. A Greek press was also established; and by offering large rewards, he incited a search for ancient manuscripts in all the libraries and cloisters of Europe. In 1515, however, Leo's attention was diverted to the French, who, under the command of their young monarch, Francis I., had invaded Italy with the intent of retaking Milan. The Swiss auxiliaries of the pope were defeated at Marignano, 14th September 1515, and the French entered Milan, and seized the duchy. Seeing his own power in jeopardy, Leo, with characteristic prudence, and despite the advice of his cardinals, hastened to the king at Bologna; and there was concluded the concordat in which the pope, in return for the ceding of Parma and Piacenza to the French, shared with the king the rights of the Gallican church. During this crisis the Duke of Urbino, who was receiving the pope's pay, had proved treacherous; and in 1516 Leo, after a hard struggle, stripped him of his duchy, and, by conferring it upon his own nephew, increased the influence of his family. In 1517, alarmed at a conspiracy that had been formed to poison him, he created thirty-one cardinals in the same day, chiefly from among his own relations. To furnish money for his extravagant pleasures, in the same year he authorized the sale of indulgences, a practice that first roused the opposition of Luther. Desirous of recovering Parma and Piacenza, which he had ceded to Francis I, he formed, in 1521, a league with Charles V., stipulating, as one of the conditions, that Luther should be deprived of the emperor's protection. The allied armies were successful; the French were driven out of Milan, and Parma and Piacenza retaken. Leo, soon after receiving the welcome tidings at his favourite villa Malliana, returned to Rome, and there, amid the festivities and rejoicings on account of the success, was attacked by a sudden malady, which, after eight days, closed his career on the 1st December 1521.

Leo X. has been happily named by Ranke a child of fortune. After his auspicious birth and influential patrons had started him on the highway to preferment, a fair amount of prudence and conduct easily led him to his exalted position; and common policy, with little effort, enabled him to hold his seat. His greatest weakness was his excessive devotion to pleasure; and this being chiefly intellectual and aesthetic, was the cause, perhaps, of his greatest virtue—his liberal patronage to men of genius. During his annual residence in the country, the intervals between hawking, hunting, and fishing, were pleasantly squandered in listening to musicians, and improvisatori. When theatres and festivals failed to please in winter, the writings of Machiavel, the poems of Ariosto, and the paintings of Raphael, were sources of new and equally eager pleasure. Even his political activity, never following matters into details, and exercising only the nobler mental faculties, gratified his ruling passion. His heavy debts rendered him unpopular; while his neglect of religious duties, and his refusal of the sacraments on his deathbed, gave, perhaps, sufficient reason for the current belief that he was a sceptic. His chief claim to remembrance is founded on the striking events of the age in which he lived. (Roscoe's Leo X.; Sismondi's Literature; Ranke's Popes.)

Leo, Leonardo, one of the most distinguished composers of the Neapolitan school of music, was born at Naples in 1694. He studied for several years at Rome under the celebrated composer G. O. Pitoni, who was also the master of Feo and Durante. On his return to Naples in 1717, Leo was appointed chapel-master of the church Santa Maria Solitaria, and afterwards became master of the conservatory La Pietà, and finally of the conservatory of Sant' Onofrio, in which last school several of the greatest composers of the eighteenth century were his pupils. Some writers have stated that he died in the year 1742, but the Abate Giuseppe Bertini, in his Dizionario Storico, &c., 1814, says that Leo died in 1745. A later writer refers to the inscription on a portrait of Leo, preserved in the Royal College of Music at Naples, according to which Leo's death occurred in 1756. He died of apoplexy, and was found dead with his head leaning on his harpsichord. Alessandro Scarlatti, and his successors Durante, Leo, and Feo, share the honour of having founded the great Neapolitan school of musical composition. Leo was a voluminous composer for the church and for the theatre, and his music is always beautiful and expressive, as well as original and scientific. Dr Burney speaks highly of Leo's music, and alludes to the Miserere in eight real parts, which was performed by more than forty voices at the Pantheon, London, in 1781. That Miserere, for two choirs without orchestra, was published at Paris, by Choron, in 1808. (G. F. G.)