ancient city of Greece, in the Peloponnesus, immediately southeast of Argos, near the head of the Argolic Gulf. According to tradition, it was founded by the mythological character Proetus, the brother of King Acrisius of Argos. Proetus was succeeded on the throne of Tiryns by Perseus, grandson of Acrisius. A later mythological king of Tiryns was Eurystheus, to whom the hero Hercules was in servitude and for whom he performed his famous labors; thus Hercules was sometimes called Tirynthius. In the historical period, Tiryns was often subject to Argos, although during the Persian Wars it was independent and in 479 bc sent troops to fight the Persians at Plataea. Some time later, probably about 468 bc, the city was taken by the Argives; after this period, Tiryns remained uninhabited and only the massive walls of its citadel were left standing, the wonder and admiration of later ages. These walls, about 7.5 m (about 25 ft) thick and constructed of huge stones, were believed by the ancient Greeks to be the work of the Cyclopses, three mythological giants.

The greatness of Tiryns dates from the prehistoric period. The city seems to have been inhabited from the 3d millennium bc and to have attained its greatest splendor in the late Mycenaean period (c. 1400–1200 bc). The palace on the summit of the citadel was excavated (1884–85) by the German archaeologist Heinrich Schliemann and until the later discoveries in Crete was considered the most complete example of the home of a prehistoric king in the Aegean area. It includes entrance gates, paved courts, large halls, vestibules, smaller rooms, and a bath; it was apparently built by stages, the complex of buildings representing both earlier and later palaces.