Thrasyllus or Thrasylus (gr. Thrasyllos, Thrasylos). an Argive, was one of the five generals of the commonwealth when Argolis was invaded by the Lacedaemonians under Agis II., in 418 BC. Agis succeeded in placing a division of his army between the Argive forces and Argos, thus cutting them off from their city, while their flank and rear were threatened by his two other divisions. Thrasyllus perceived the danger of this position, and, together with Aleiphron (one of his fellow-citizens and a proxenus of Lacedaemon), obtained an interview with Agis, and induced him by the hope of a permanent peace to grant them a truce for four months. Thrasyllus and Alciphron, however, had taken this step without being authorized; and the Argives, who imagined that they had been on the point of gaining an easy victory over the Lacedaemonians. shut in as the latter were between them and the city, were highly exasperated, and began to stone Thrasyllus in the military court which was always held just outside the walls of Argos after an expedition. He saved his life only by taking refuge at an altar, and he was punished by the confiscation of his property. (Thuc. v. 59, 60.)