Ivaylo (died 1281), also spelled Ivailo (Bulgarian: Ивайло), was a rebel leader who ruled briefly as tsar of Bulgaria.

Beset by foreign and domestic enemies, which included the Bulgarian nobles, he was eventually forced into exile among the Mongols, where he presented himself as a dethroned vassal.

[2] Ivaylo's reign as a monarch has been used as an example of early anti-feudal class warfare by Marxist historians and has been translated through folk songs, traditions and legends.

Quite deliberately, the Russian Slavologist Sreznevsky decided that Pachymer had wrongly transmitted the Slavic word "bardokva" without any logic in this β ← κ transition.

Burdokva means lettuce, salad, the "blue gall" plant, and was found as a Bulgarian dialect word in the 19th century (BER 2007, 101–102).

But if some positive etymology is sought, it should rather be connected with Mongolian khurd - 'speed', khurdan, khurddah - 'quick, agile' (Kruchkin 2006, 863) The current form "Ivaylo" is an accidental bastardization from K. Irechek's work.

The name Ivlei and its variants Ivliy, Ivoil, Ivoilo are found among Russians and Ukrainians and are considered Turkic (Cuman) in origin.

[6] Prof. T. Balkanski believes that the name Ival, Ivail evolved into the Bulgarian linguistic environment quickly to the form Volo.

He allegedly saw visions of himself grounded in the medieval Christian tradition,[8] accomplishing great deeds and ridding Bulgaria of its troubles, including above all the frequent incursions by the Mongols of the Golden Horde under Nogai Khan.

Although Ivaylo was able to extend his authority across much of the country at the helm of his peasant army, he also met with resistance, and the capital Tarnovo remained under the control of the emperor Michael Asen II and his mother Maria Kantakouzena, which made him need to besiege it and conquer it militarily in 1279.

Later Michael VIII changed his plan, married his eldest daughter Eirene to Ivan Asen III, a descendant of Bulgaria's ruling dynasty living at the Byzantine court, and dispatched troops to place him on the throne.

A rumor of Ivaylo's death caused panic in Tarnovo, where the nobility surrendered to a new Byzantine army and accepted Ivan Asen III as emperor.

Others might argue that while the troubled social conditions in the 1270s certainly contributed to the revolt, Ivaylo's rise to power may be more closely comparable to a nationalist reaction such as that led (albeit with religion as a strong inspiration) by Joan of Arc.