Initially with four brothers; assumes the title of King

The first Serbian king, under whom Duklja was the first Serbian state to achieve more widespread international recognition. Originally, Mihailo (Michael) appeared to have shared power (or perhaps been "the first among equals") with his four brothers. An early threat by a breakaway rebellion in Trebinje was faced by the coordinated action of the brothers, and the agreement that bound them in so doing, brokered by their mother, is perhaps the oldest known treaty in Serbian history.

While in no imminent danger from that side, Mihailo found it favorable to further strengthen ties with Byzantium around 1052, gaining a patrician title and marriage to a Greek princess in the process. This might have implied titular recognition of Constantinople's authority, but no real concessions on his part. It corresponded to the current balance of forces and bought some 20 years of peace and prosperity to his land.

Matters started to change after 1071, the year of Byzantium's key Asian debacle at Manzikert, as well as the loss of south Italy to the Normans. Following the Slavic uprising in Macedonia, Mihailo broke his neutrality and sent off troops under his son Bodin to aid the rebels, upon their request. Despite initial successes, the rebellion failed toward the end of 1072, with Bodin captured and only much later saved. After this, Mihailo begins looking for support westward - to the Pope. This came as a result of his alienation from the Byzantines, but also from a desire to instate an independent archbishopric within his realm, and finally to obtain a royal title. In the aftermath of the Church schism of 1054, Pope Gregory VII had an interest in bestowing these on rulers in the rift area, and Mihailo was granted one, sometime prior to 1077. Thereafter, Duklja (Zeta) is referred to as a kingdom, until its reduction in the following century.

Having sealed ties with the Normans through the marriage of his heir Bodin, Mihailo died in 1081, after a rule of 30 or so years. He left us St. Michael's Church in Ston, north of Dubrovnik, a small church following mostly an early Byzantine style, which contains the oldest known fresco portrait of a Balkan Slavic ruler.