This date represents a couple of significant anniversaries in the history of Christian-Muslim relations.

In 1192 Richard the Lion-Heart was captured and imprisoned by Leopold V of Austria after signing a treaty with Saladin ending the Third crusade.

And in 1522 Suleiman the Magnificent accepted the surrender of the surviving Knights of Rhodes, who were allowed to evacuate, eventually settling on Malta to become the Knights of Malta.

Frye in “Substance and Evidence”:

And just as hope is the beginning of faith, so love is the end of it.  Let us think, for example, of a Christian and a Muslim, facing each other in one of the Crusades.  Neither of them knows the first thing about the other man’s religion, but they’re both convinced that it is utterly and damnably wrong; they are even prepared to die for that conviction.  There must be something the matter with a faith that expresses itself as a desire to kill somebody who doesn’t share it.  A profoundly Christian writer, Jonathan Swift, remarked that men have just enough religion to make them hate, but not enough to make them love one another.  To which we may add that those who have no religion don’t seem to hate any the less on that account.  The general principle here is that whatever reflects any credit on humanity is always attached to something else that’s silly or vicious.  As Jesus ben Sirach, the author of Ecclesiastes, says: “What race is worthy of honour?  The human race.  What race is unworthy of honour?  The human race.” [10:19, RSV] (CW 4, 324)