The "Wujing Zongyao" states that the crossbow used "en masse" was the most effective weapon against northern nomadic cavalry charges. Even if they failed, the quarrels were too short to be used as regular arrows so they couldn't be used again by nomadic archers after the battle. The crossbow's role as an anti-cavalry weapon was later reaffirmed in Medieval Europe when Thomas the Archdeacon recommended them as the optimal weapon against the Mongols. Elite crossbowmen were used to pick off targets as was the case when the Liao Dynasty general Xiao Talin was picked off by a Song crossbowman at the Battle of Shanzhou in 1004.