库苏古尔省
The Khalkha eventually submitted to Qing rule in 1691 by Zanabazar's decision, thus bringing all of today's Mongolia under the rule of the Qing dynasty but Khalkha "de facto" remained under the rule of Galdan Boshugtu Khaan until 1696. The Mongol-Oirat's Code (a treaty of alliance) against foreign invasion between the Oirats and Khalkhas was signed in 1640, however, the Mongols could not unite against foreign invasions. Chakhundorj fought against Russian invasion of Outer Mongolia until 1688 and stopped Russian invasion of Khövsgöl Province. Zanabazar struggled to bring together the Oirats and Khalkhas before the war.