 Christian Georgia was repeatedly attacked starting in 1220 , and in 1243 Queen Rusudan formally submitted to the Mongols , turning Georgia into a vassal state which then became a regular ally in the Mongol military conquests . Hethum I of Cilician Armenia submitted in 1247 , and over the following years encouraged other monarchs to enter into a Christian @-@ Mongol alliance . He sent his brother Sempad to the Mongol court in Karakorum , and Sempad 's positive letters about the Mongols were influential in European circles . 
