Картлис цховреба
In 1033, the royal court faced another dynastic trouble, this time with Bagrat's half-brother Demetrius of Anacopia, a son of George I of his second marriage with Alda of Alania. Demetrius and Alda lived in Anacopia, a fortress in Abkhazia, which had been bequeathed to them by the late king George I. The efforts by Bagrat's mother Mariam to win Demetrius's loyalty to the crown went in vain. Threatened by Bagrat, Alda defected to the Byzantines and surrendered Anacopia to the emperor Romanos III in 1033, who honored her son Demetrius with the rank of "magistros". According to "The Georgian Chronicles": King Bagrat defeated a united army of his opponents and then besieged Anacopia, then he went back, leaving Otago Chachasdze and his army to take charge of the fortress.