information:extraction
Battle of Yongqiu

However, the Battle of Yongqiu, in the spring of 756, went badly for An Lushan. Although his army, under Linghu Chao, was numerous, it was unable to make further territorial gains due to the failure to wrest control of Yongqiu (modern Qi County, Kaifeng, in Henan) and (later) the nearby Suiyang from the Tang defenders led by Zhang Xun. This prevented the Yan forces from conquering southern China, before the Tang were able to recover. The Yan army did not take control of Suiyang until after the Siege of Suiyang (January–October 757), almost two years after their initial capture of Luoyang.