Emperor of Bulgaria in the context of "Principality of Bulgaria"

Peter II, born Theodor, also known as Theodor-Peter (Bulgarian: Теодор-Петър; died in 1197), was the first emperor or tsar of the restored Bulgarian Empire from 1185 to 1197. He hails from the Byzantine theme of Paristrion, although his exact place and date of birth are unknown.

He and his younger brothers, Asen and Kaloyan, were mentioned as Vlachs in most foreign contemporaneous sources but they were probably of a mixed Vlach, Bulgarian, and Cuman origin. In 1185, Theodor and Asen approached the Byzantine Emperor Isaac II Angelos in Thrace, demanding an estate in the Balkan Mountains. After the Emperor refused and humiliated them, they decided to incite a rebellion, taking advantage of the discontent that a new tax had caused among the Bulgarians and Vlachs. To convince their compatriots to join them, they had native prophets declare that Saint Demetrius of Thessalonica had abandoned the Romans in favour of the Bulgarians and Vlachs. Before the end of the year, Theodor was crowned Emperor of Bulgaria, taking the name Peter and adopting the insignia used only by emperors.

Ivan Asen I, also known as Asen I or John Asen I (Bulgarian: Иван Асен I; died in 1196), was emperor or tsar of Bulgaria from 1187/1188 to 1196 as co-ruler with his elder brother, Peter II. Hailing from the Byzantine theme of Paristrion, his exact place and date of birth are unknown. Most contemporaneous chronicles describe Asen and his brothers, Theodor (Peter) and Kaloyan, as Vlachs but they were probably of mixed Bulgarian, Cuman and Vlach ancestry.

In 1185, Asen and Theodor went to see the Byzantine Emperor Isaac II Angelos in Thrace to demand an estate in the Balkan Mountains. After the Emperor refused and humiliated them, the brothers persuaded their Bulgarian and Vlach compatriots to rise up against the Byzantine Empire. Before the end of the year, Theodor was crowned Emperor of Bulgaria, taking the name Peter. After Isaac II defeated them in early 1186, Asen and Peter fled north over the Danube but returned in the autumn, accompanied by Cuman reinforcements. They captured Paristrion and began pillaging the nearby Byzantine territories.

The Uprising of Georgi Voyteh (Bulgarian: Въстание на Георги Войтех, romanized: Vastanie na Georgi Voyteh), or the Slavic uprising against the Byzantine rule (Serbian: Словенски устанак против византијске власти, romanized: Slovenski ustanak protiv vizantijske vlasti) was a wide South Slavic uprising against the Byzantine rule, that broke out in central Balkan regions soon after the devastating Byzantine defeat in Asia Minor, at the Battle of Manzikert (1071). The movement was initiated by Bulgarian leaders in the theme of Bulgaria, with assistance from the Serbian prince Michael I of Duklja, whose son Bodin was accepted by the rebels and proclaimed as emperor of Bulgaria, under the name Peter (1072). After some initial expansion, and several clashes with the Byzantines, the rebels were defeated by 1073. That was the second major attempt to restore the Bulgarian Empire, after the failed Uprising of Peter Delyan in 1040–1041.

Theodore II Doukas Laskaris or Ducas Lascaris (Greek: Θεόδωρος Δούκας Λάσκαρις, romanized: Theodōros Doúkās Láskaris; November 1221/1222 – 16 August 1258) was Emperor of Nicaea from 1254 to 1258. He was the only child of Emperor John III Doukas Vatatzes and Empress Irene Laskarina. His mother was the eldest daughter of Theodore I Laskaris, who had established the Empire of Nicaea as a successor state to the Byzantine Empire in Asia Minor after the crusaders captured the Byzantine capital, Constantinople, during the Fourth Crusade in 1204. Theodore received an excellent education from two renowned scholars, Nikephoros Blemmydes and George Akropolites. He made friends with young intellectuals, especially with a page of low birth, George Mouzalon. Theodore began to write treatises on theological, historical and philosophical themes in his youth.

Emperor John III arranged for Theodore to marry Elena Asenina in 1235, to forge an alliance with her father, Ivan Asen II, Emperor of Bulgaria, against the Latin Empire of Constantinople. According to Theodore himself, their marriage was happy, and they had five or six children. From 1241, Theodore acted as his father's lieutenant in Asia Minor during his frequent military campaigns in the Balkan Peninsula. From around 1242, he was his father's co-ruler, but was not crowned as co-emperor. During this period, his relationship with some prominent aristocrats, particularly Theodore Philes and Michael Palaiologos, grew tense.