Turks. Although the Byzantine Empire and Georgia had centuries-long cultural and religious ties, and the Seljuqs posed a substantial threat to the empire itself, Constantinople's aggressiveness on the Caucasian political scene contributed to an atmosphere of distrust and recrimination, and prevented the two Christian nations from effective cooperation against the common threat. With assertion of the Georgian Bagratid hegemony in the Caucasus being the cornerstone of Bagrat's reign, his policy can be understood as the attempt to play the Seljuqs and Byzantines off against one another. Dynastic wars Shortly after Bagrat's ascension to the throne, Constantine VIII sent in an army to take over the key city-fortress of Artanuji (modern Ardanuç, Turkey) on behalf of the Georgian Bagratid prince Demetre, son of Gurgen of Klarjeti, who had been dispossessed by Bagrat IV's grandfather, Bagrat III, of his patrimonial fief at Artanuji early in the 1010s. Several Georgians nobles defected to the Byzantines, but Bagrat's loyal subjects put up a stubborn fight. Constantine's death in 1028 rendered the Byzantine invasion abortive, and, in 1030, Queen Mariam paid a visit to the new emperor Romanos III (). She negotiated a peace treaty, and returned with the high Byzantine title of curopalates for her son in 1032. Mariam also brought him the Byzantine princess Helena Argyre as wife. Helena was a daughter of Basil Argyros, brother of Emperor Romanos, and the marriage was a diplomatic effort to establish a strategic association. However, Helena's death shortly afterwards at Kutaisi presented the Georgian court with the opportunity to pursue yet another diplomatic initiative through Bagrat's marriage with Borena, daughter of the king of Alania, a Christian country in the North Caucasus. In 1033, the royal court faced another dynastic trouble, this time with Bagrat's half-brother Demetre, a son of George I of his second marriage with Alda of Alania. Demetre and Alda lived in Anacopia, a fortress in Abkhazia, which had been bequeathed to them by the late king George I. Although an attempt by some great nobles to exploit Demetre's possible aspirations to the throne in their opposition to Bagrat's rule failed, the Georgian court's efforts to win his loyalty also went in vain. Threatened by Bagrat, the dowager queen Alda defected to the Byzantines and surrendered Anacopia to the emperor Romanos III who honored her son Demetre with the rank of magistros. In 1039, Demetre returned to Georgia with Byzantine troops. This time,