First Crusade: 1095 on command of pope Urban II.

Until January 1098 a total of 40 capital cities and 200 castles conquered (number of slain unknown) [WW30]
After 6/3/98 Antiochia (then Turkish) conquered, between 10,000 and 60,000 slain. 6/28/98 100,000 Turks (incl. women and children) killed. [WW32-35]
Here the Christians "did no other harm to the women found in [the enemy's] tents - save that they ran their lances through their bellies," according to Christian chronicler Fulcher of Chartres. [EC60]
Marra (Maraat an-numan) 12/11/98 thousands killed. Because of the subsequent famine "the already stinking corpses of the enemies were eaten by the Christians" said chronicler Albert Aquensis. [WW36]
Jerusalem conquered 7/15/1099 more than 60,000 victims (Jewish, Muslim, men, women, children). [WW37-40]
In the words of one witness: "there [in front of Solomon's temple] was such a carnage that our people were wading ankle-deep in the blood of our foes", and after that "happily and crying for joy our people marched to our Saviour's tomb, to honour it and to pay off our debt of gratitude."
The Archbishop of Tyre, eye-witness, wrote: "It was impossible to look upon the vast numbers of the slain without horror; everywhere lay fragments of human bodies, and the very ground was covered with the blood of the slain. It was not alone the spectacle of headless bodies and mutilated limbs strewn in all directions that roused the horror of all who looked upon them. Still more dreadful was it to gaze upon the victors themselves, dripping with blood from head to foot, an ominous sight which brought terror to all who met them. It is reported that within the Temple enclosure alone about ten thousand infidels perished."