The Battle of Maskin (Arabic: معركة مسكن), also known as the Battle of Dayr al-Jathaliq (Arabic: معركة دير الجثاليق) from a nearby Nestorian monastery, was a decisive battle of the Second Fitna (680s-690s). It was fought in mid-October 691 near present-day Baghdad on the western bank of the river Tigris, between the army of the Umayyad caliph Abd al-Malik ibn Marwan and the forces of Mus'ab ibn al-Zubayr, governor of Iraq for his brother, the Mecca-based rival caliph Abd Allah ibn al-Zubayr.