The thalassocracy of Samos spans the career of the tyrant, Polycrates, there. The dates of the tyrant are somewhat uncertain and variable, but at some time prior to 534 BC, he and his brothers staged a coup during a festival at Samos. Samos happened to have a large navy of pentekonters. Becoming a ship collector, he attacked and subdued all the neighbouring islands, adding their ships to his fleet. Finally he added a new model, the trireme. His reign came to an end about 517 BC when, taking up the Great King's invitation to a friendly banquet for a discussion of prospects, he was suddenly assassinated. There were no prospects.