 However, at the same time that Baron Ungern was taking control of Urga, a Soviet-supported Communist Mongolian force led by Damdin Sükhbaatar was forming in Russia, and in March they crossed the border.Ungern and his men rode out in May to meet Red Russian and Red Mongolian troops, but suffered a disastrous defeat in June.In July 1921, the Communist Soviet-Mongolian army became the second conquering force in six months to enter Urga.