The Alans and Georgians probably collaborated in the Christianization of the Vainakhs and Dvals in the 12th and 13th centuries, Georgian missionaries were active in Alania and the Alan contingents were frequently employed by the Georgian monarchs against their Muslim neighbors. The Alanian-Georgian alliance was cemented in the 1060s, when the Alans struck across Muslim Arran and sacked Ganja. In the 1120s King David the Builder of Georgia visited the Darial to reconcile the Alans with the Kipchaks, who thereupon were allowed to pass through Alania to the Georgian soil. David's son, Demetre I, also journeyed, c. 1153, to Alania accompanied by the Arab historian Ibn al-Azraq. The alliance culminated in 1187, when the Alanian prince David Soslan married Queen Tamar of Georgia, a half-Alanian herself, with their descendants ruling Georgia until the 19th century. The medieval Alanian princesses also married Byzantine and Russian Rurikid rulers more than once. For instance, Maria the Ossetian, who founded the Convent of Princesses in Vladimir, was the wife of Vsevolod the Big Nest and grandmother of Alexander Nevsky.