Battle of Ajnadayn
The Battle of Ajnadayn (Arabic: معركة أجنادين) was fought in July or August 634 (Jumada I or II, 13 AH), in a location close to Bayt Jibrin; it was the first major pitched battle between the Byzantine (Roman) Empire and the army of the Arab Rashidun Caliphate. The result of the battle was a decisive Muslim victory.