Melisende of Arsuf was born in 1177.

Battle of Arsuf happened on 1191-09-07.

You can only get to it after Altair fails the third and final assassination in Jerusalem. If you exit Jerusalem and go into the Kingdom and check the map, you'll see that the way to Arsuf has opened up. It's Southeast of Acre.

Battles of Acre, Arsuf.

In Asia, King Baldwin I of Jerusalem captures Arsuf and Caesarea. In Europe, Robert Curthose, duke of Normandy, signs the Treaty of Alton, which established Henry I as the King of England.