Uprising of Ivaylo - Wikipedia
en.wikipedia.org
Ivaylo was a Bulgarian peasant who rose up against the rule of tsar Constantine Tikh, whose reign saw the loss of territory to various foreign adversaries. Ivaylo quickly gathered followers to his cause, and within a year or so of launching his rebellion he took control of the Bulgarian capital, Tarnovo. His victory was short-lived, however, and he was caught in a two front war against the Mongols and the Byzantines. As he marched north to confront the former, the nobility raised a new tsar to replace him. Without any allies, Ivaylo was captured by the Mongols and murdered under their watch.
Was there any way he could've succeeded in his aims, and stayed tsar of Bulgaria? From what I can gather from the wikipedia article on Ivaylo, it seems Michael VIII planned for his daughter to marry him to forge an alliance, but he decided to strike a deal with Ivan Asen III instead. Assuming Ivaylo and the Byzantines become allies, could he then focus all of his forces against the Mongols and consolidate his control over Bulgaria? Could he stem or reverse its decline?