The Mongols also helped them more directly by attacking their enemies. Plus, Moscow was at the headwaters of four rivers, which made it well positioned for trade. And because they were kind of the allies of the Mongols, the Mongols rarely attacked them, which meant that lots of people went to Moscow because it was relatively safe, including churchy people. And in fact, Moscow became the seat of the Eastern Orthodox Church in 1325, when the metropolitan Peter moved there. So you might think that the Muscovites would be grateful for all of this help from the Mongols. But you would be wrong. In fact, as the Mongols' position weakened in Russia in the latter half of the 14th century, one of Moscow's princes, Dmitry Donskoy, made war on them and inflicted the first major defeat of Mongols in Russia at the Battle of Kulikovo Field.