In 1346, Dobrotitsa and his brother Theodore were sent along with 1,000 soldiers by the Dobrujan ruler Balik to help the Byzantine Empress Anna of Savoy in the civil war against John VI Kantakouzenos, but were defeated by George Phakrases. The following year, after the death of Balik, he became the ruler of Dobruja. In 1348 Dobrotitsa took over the fortress of Midia and by 1356 managed to seize Kozyak (present-day Obzor) and Emona from the Byzantines.