An energetic and ambitious ruler, Michael Shishman led an aggressive but opportunistic and inconsistent foreign policy against the Byzantine Empire and the Kingdom of Serbia, which ended in the disastrous Battle of Velbazhd that claimed his own life.

He soon became a leading noble in the internal affairs of the country and, on the childless death of young George Terter II in 1323, Michael Shishman was elected emperor of Bulgaria by the nobility.

[7] The sudden death of George Terter II had been followed by a brief period of confusion and uncertainty, which was exploited by the Byzantine emperor Andronikos III Palaiologos.

The Byzantines overran northeastern Thrace and captured a number of important cities including Yambol, Lardea, Ktenia, Rusokastro, Anchialus, Sozopol and Agatopol.

At the same time, a Byzantine-sponsored pretender, Voysil, brother of the former Bulgarian emperor Smilets (r. 1292-1298), ensconced himself in Krăn, controlling the valleys between the Balkan mountains and Sredna Gora from Sliven to Kopsis.

[10] Despite the loss, Michael Shishman was able to expel Voysil and fully recover Bulgarian control over northern and northeastern Thrace in 1324 which had been taken by the Byzantines in the previous year during the interregnum.

[13] On a council held in Constantinople on the relations with Bulgaria, it was decided that the two countries should begin negotiations despite the calls for punishing the Bulgarians for the invasion.

[16][17] The marriage cemented the peace treaty with the Byzantine Empire but the need for an ally against the Serbs made Michael Shishman prone to make concessions.

[21] The Bulgarian ruler sent a detachment of 3,000 cavalry, commanded by Ivan the Russian, from Yambol to guard the Imperial Palace in Constantinople and Andronikos II but his intentions were to capture the old emperor and the city.

When Michael Shishman understood that his plans were revealed he sent Ivan a letter with a single feather to retreat which meant that the orders had to be promptly executed.

[25] Another showdown in front of Adrianople 60 days later ended without battle and with the renewal of the peace treaty in October 1328, after which Michael Shishman returned to his country, but not before securing a large payoff.

[27] At the beginning of the next year the Bulgarian emperor requested a personal meeting with his Byzantine counterpart to negotiate a definitive treaty and joint military operations against the growing power of Serbia.

[31] In 1330, expecting to join the army of Andronikos III advancing from the south, Michael Shishman marched on Serbia with a large force of 15,000 troops, including reinforcements from his vassals and allies from Wallachia and Moldavia.

However, in the morning of 28 July, the main Serbian reinforcements, 1,000 heavily armed Catalan horsemen mercenaries under the command of the King's son Stephen Dušan arrived, and the Serbs broke their word and attacked the Bulgarians.

[37] The early 15th-century Bulgarian scholar and cleric Gregory Tsamblak says that Michael Shishman was captured and killed by the son of the Serbian king, Stephen Dušan.

[38] Michael Shishman is considered a vain, aggressive, and opportunistic ruler, whose Protean foreign policy perhaps contributed to the battle that put an end to his life.

[37] According to Kantacouzenos he desired to expand the country from Byzantium to the Istros, i. e. from Constantinople to the Danube[17][20] which makes him the last medieval Bulgarian ruler who effectively attempted to capture the Byzantine capital.