(from Ζεύς, Δίος Jupiter, and κόπος children), or sons of Jupiter, the common designation of the brothers Castor and Pollux. According to the myths, which however are very variously narrated by different authors, these twins were the children of Tyndareus, king of Sparta, and Leda. According to other accounts they were the children of Jupiter and Leda. In other versions of the same myth Leda is mentioned as having produced two eggs, from one of which sprang Castor and Clytemnestra, and from the other Pollux and Helen. The place is as variously given as the manner of their birth. Some authors give Amyclae on the Eurotas, others Mount Taygetus in Laconia, others Thalamis in Elis, others various islands of the Ægean. As soon as they grew up, they became distinguished for their skill in all athletic sports. Castor took under his especial patronage all equestrian exercises; while Pollux became equally renowned for his skill in boxing, of which he became, in after times, the tutelary god. It is in allusion to this fact that Horace (lib. i., ode 12) talks of the

The leading events in the lives of the Dioscuri are three in number. The first of these is their invasion of Attica, in which they rescued their sister Helen, who had been carried off by Theseus; the second, their share in the Argonautic expedition; and the third, their battle with the sons of Aphareus, in which Castor was killed. Pollux, finding his brother dead on the battle-field, implored Jupiter to be allowed to die along with him. Jupiter gave him his choice either to live as an immortal with the other gods, or to spend his time alternately, day by day, in Hades and in the upper world. According to other accounts the brothers were translated to heaven together after death, and ranked among the stars under the name of Gemini. The worship of the Dioscuri was very widely diffused throughout the ancient world; but especial honours were paid to them in Sparta and the Dorian colonies of Magna Graecia. It is in allusion to this fact that Mr Macaulay in his Lay of the battle of the Lake Regillus, in which they fought on the side of Rome, describes them as accounting for their appearance on that occasion—

By many names men call us, In many homes we dwell; Well Samothracia knows us, Cyrene knows us well: Our house in gay Tarentum Is hung each morn with flowers; High up the walls of Syracuse Our noble portal towers; But by the proud Eurêas Is our dear native home, And for the right we come to fight Before the ranks of Rome.

They generally appear in the ancient classics as kindly, and disposed to help and protect all such as do them due honour. On this account their worship was carefully observed by travellers, whether on land or sea. Sailors were consequently very scrupulous in paying their homage to these deities both before and after a voyage; and even in the midst of a storm their prayers were believed to be not unheard by the Tyndaridae. Hence Horace describes them as divinities—

quorum simul alba nautis Stella refusa, Decidit saxis agitatus humor; Concidunt venti fagatinum nubes Et simul quod sic volvere Ponto Unda recumbat.

Though their worship was perhaps most carefully observed among people of Dorian origin, they were held in no small veneration at Rome. It was the popular belief in that city from an early period, that the great day of the Regillus had been decided by their interposition. They had fought, it was said, armed and mounted, at the head of the legions of the commonwealth, and had afterwards carried the news of the victory with incredible speed to the city. The well in the forum at which they alighted was pointed out. Near the well rose their ancient temple. A great festival was kept in their honour on the Ides of Quintilis, believed to be the anniversary of that battle, and sumptuous sacrifices were offered to them at the public charge. It was further ordained that a grand muster and inspection of the equestrian body should be part of the ceremonial performed. All the knights, clad in purple, and crowned with olive, were to meet at a temple of Mars in the suburbs. Thence they were to ride in state to the forum, where the temple of the twins stood. This pageant was during several centuries considered as one of the most splendid sights of Rome. In the time of Dionysius the cavalcade consisted of 5000 horsemen, all persons of fair repute and independent fortune.