In 1267, Mengu-Timur issued a diploma – jarliq – to exempt Rus' clergy from any taxation and gave to the Genoese and Venice exclusive trading rights in Caffa and Azov. Some of Mengu-Timur's relatives converted to Christianity at the same time and settled among the Rus' people. One of them was a prince who settled in Rostov and became known as Tsarevich Peter of the Horde (Peter Ordynsky). Even though Nogai invaded the Orthodox Christian Byzantine Empire in 1271, the Khan sent his envoys to maintain friendly relationship with Michael VIII Palaiologos, who sued for peace and married one of his daughters, Euphrosyne Palaiologina, to Nogai. Mengu-Timur ordered the Grand prince of Rus to allow German merchants free travel through his lands. This gramota says: