Andrea, a celebrated Italian architect, was born at Vicenza in 1518. He began life as a sculptor, but was afterwards induced by his friend Trissino the poet to direct his attention to architecture. His generous patron took Palladio with him to Rome on three several occasions, where the young artist made a diligent study of the best specimens of ancient architecture of which that city could boast. Returning to his native town in 1547, he set zealously to work both as a practical architect and as an illustrator and expounder of his favourite art. He attained an unbounded popularity as a master of architectural design. Noble and commoner vied with each other to overwhelm the rising artist with commissions; and Pope Paul III. summoned him to Rome to obtain his professional Palladio's advice regarding St Peter's. An estimate of Palladio's character as an architect will be found in the article Architecture. He gave the world the benefit of his artistic studies at Rome in his Antichità di Roma, published at Rome in 1554, and frequently reprinted. His greatest work, however, was his Architettura, in four books, published at Venice in 1570, and frequently reprinted, re-edited, and translated. It appeared in London in 1715, in two folio volumes, under the title, Architecture, in English, Italian, and French, with Notes and Observations by Inigo Jones; revised, designed, and published by Leoni. This edition was often reprinted and re-edited, and appeared both in French and Italian. The best edition of the Architettura is that of Vicenza, in Italian and French, in four large folio volumes, 1776-85. A new edition of his works was published in Paris, 1825-42, in folio. Palladio died in August 1580, while engaged on his greatest work, the Teatro Olimpico at Vicenza.

PALIADIUM (Παλαιδίον), an image or statue of the goddess Pallas Athene or Minerva, kept carefully hidden, and revered as the safeguard of the place where it lay. Among the ancient images of the goddess, by far the most celebrated was the Palladium of Troy, said to have been thrown from the top of Olympus by the hand of Zeus, and to have been picked up and preserved by Hus on the building of the city. This statue was about 3 cubits high, and represented the goddess sitting with a spear in her right hand, and in her left a distaff and spindle. The safety of Troy was universally regarded as depending upon the preservation of the Palladium. Ulysses and Diomedes were accordingly commissioned during the Trojan war to steal it. They effected their object despite the wrath of Pallas, who is said to have infused temporary life and motion into her image to intimidate the impious Greeks. (Virgil, Æneid, ii. 164, &c.) According to other accounts, the genuine Trojan Palladium was conveyed by Æneas to Italy, and was subsequently preserved with the utmost secrecy and veneration in the temple of Vesta. To account for the discrepancy in these traditions, some have alleged that the image stolen by the Greeks was simply an imitation of the real one; while others affirm that Troy contained two Palladia equally genuine. In Greece, Argos and Athens both claimed the honour of possessing the ancient Trojan Palladium; and in Italy, the cities of Rome, Lavinium, Luceria, and Siris put forward similar pretensions.

On passing into European languages, the word palladium came to signify any peculiar law or privilege regarded as the safeguard of the liberties of the people, or, in general, whatever affords effectual protection and safety. The term palladium has also been applied to a metal discovered by Dr Wollaston in 1803, associated with platinum, from which it is obtained, and which it resembles in colour and lustre.