Complex sentence: After the capture of Acre, Richard decided to march to the city of Jaffa, where he could launch the attack on Jerusalem but on 7 September 1191, at Arsuf, north of Jaffa, Saladin attacked Richard's army.
Split into simpler sentences: After the capture of Acre, Richard decided to march to the city of Jaffa, from where he could launch the attack on Jerusalem. However, on 7 September 1191, at Arsuf to the north of Jaffa, Saladin attacked Richard's army.