A year later , the Song generals fielded their armies to occupy the old capitals of the Song .
Generals were completely repelled by the Mongol garrisons under Tachir , a descendant of Boorchu , who was a famed companion of Genghis Khan .
A year later , the Song generals fielded their armies to occupy the old capitals of the Song , but they were completely repelled by the Mongol garrisons under Tachir , a descendant of Boorchu , who was a famed companion of Genghis Khan .