Following the rule of Ivan Asen II, there were several mediocre tsars: his sons, Kaliman and Michael II Asen, from his two marriages. Neither was a successful ruler, and Tartar invasions from the north continued. During their rule, the Nicean Empire captured Macedonia and the Rhodopes, while the Comnenus family controlled Epirus and Albania. Eventually the bolyar Constantine Tikh ascended to the throne in 1257, but proved to be a mediocre ruler and was unable to protect against the Byzantine Empire and Tartars.
After Constantine Tikh raised taxes, the peasant Ivailo, formerly a swineherd in Dobroudja, began to gain power. A gifted speaker, Ivailo convinced the other peasant that he was an instrument of God sent to liberate them from heay taxes and continuing attacks from the outside. Ivailo's power culminated in 1277, when a peasant revolt broke out an enabled Ivailo to repel the Tartars. With his army, the new tsar was able to discourage the Tartars and turned his sights on Constantine Tikh.
With his army growing with each new town liberated, Ivailo began to be regarded as a patriot able to defeat the aging and inept Constantine Tikh. Once he confronted the former tsar, Ivailo won and besieged the capital. However, the Byzantines attacked him from the rear and he was forced to seek reconciliation.
Ivailo ruled from 1278-1280, defending the kingdom from constant assault on all sides. Eventually the Byzantines attacked again, and although Ivailo was a skilled commander and was consistently able to defeat the Byzantines, he lost peasant support and was forced to turn to his former enemies, the Tartars, who killed him in their camp. Ivailo's fame continued, however, and his name was frequently used to attract support for other rulers. His nicknames derive from his peasant origins.