Agatho, pope from 678 to 681, was born in Sicily. He is noteworthy as the pope who ordered St. Wilfrid to be restored to his bishopric at York in 679, and as the first to cease
payment of the tribute hitherto paid on election to the emperor at Constantinople. It was during his pontificate that the Sixth Ecumenical Council was held at Constantinople, to which he sent his legates and those from a Roman council held in 679. Agatho died on January 10, 681.
... who assumed power for any period of time without a legitimate basis of authority.
The first to have the title of "Tyrant" was Pisistratus in 560 BC.
In modern times ...