Let him who is without sin cast the first severed head.
Christians tossing severed heads into Nicaea during the siege in 1097. BNF MS Fr 2630 f.22v via Wikimedia
“As many as descended remained there with their heads cut off at the hands of our men; moreover, our men hurled the heads of the killed far into the city, that they (the Turks) might be the more terrified thereat.”
August. C. Krey, The First Crusade: The Accounts of Eyewitnesses and Participants, (Princeton: 1921), 101-103 Via Internet History