The battle of the Horns of Hamah (13 April 1175) was an important battle during Saladin's campaign to gain control of Syria and saw him defeat a combined army from Aleppo and Mosul (Saladin's Conquest of Syria).
In May 1174 Nur ad-Din, ruler of Syria, died. At the time of his death he ruled Damascus and Aleppo directly. His nephew Saif-ad-Din ruled Mosul as a vassal ruler, while Saladin ruled Egypt. Saladin was officially a vassal of Nur ad-Din, and had acknowledged his authority, although Nur ad-Din never entirely trusted him. At the time of his death Nur ad-Din was probably planning a campaign to depose Saladin.
When Nur ad-Din died his son and heir, as-Salih, was only 11. Almost inevitably there was a battle for control of the young monarch. At the time of his father's death the young king was at Damascus, and a local regent was appointed. Saif-ad-Din decided to repudiate as-Salih's authority and invaded the lands controlled by Aleppo. He split his army and sent his general, Gümüshtigin, to Aleppo. Gümüshtigin became part of the ruling group at Aleppo and abandoned his allegiance to Saif-ad-Din. As-Salih decided to move to Aleppo, and Gümüshtigin took command of the party send to fetch him. On his return to Aleppo Gümüshtigin seized control of the city.
The ruling part in Damascus now invited Saladin to take control. He arrived in October 1174, secured in control of the city and them moved to besiege Aleppo (30 December 1174-March 1175). On his way he captured the city of Homs, but not the citadel. The defenders of Aleppo eventually took advantage of this. They formed an alliance with the Crusaders, who moved to Homs, joined with the garrison in the citadel and threatened Saladin's army in the city. This forced Saladin to lift the siege of Aleppo and move back to Homs. The Franks withdrew and Saladin was able to capture the citadel of Homs. He also captured Baalbek, securing control of all of Syria to the south of Hamah.
This success finally convinced Saif-ad-Din to cooperate with the authorities in Aleppo to deal with the upstart Saladin. Saif-ad-Din was forced to split his army, as his brother Imad-ad-Din had joined with Saladin. Saif-ad-Din led part of the army against his brother, and sent another brother, Izz-ad-Din, to join with the army of Aleppo.
At this stage Saladin was outnumbered. He had left most of his army behind in Egypt when he first came to Damascus. Reinforcements, under the command of his nephews Farrukh-Shah and Taqi-ad-Din, were on their way, but until they arrived Saladin tried to avoid battle.
The two sides met at Hamah and negotiations began. Saladin agreed to most of Aleppo's terms - he agreed to rule Damascus as as-Salih's governor, to hand back Homs, Hamah and Baalbek and to acknowledge the supremacy of Aleppo. Negotiations only fell apart when Aleppo demanded that Saladin return Rahba. This town had belonged to his uncle Shirkuh, but had been confiscated by Nur ad-Din after Shirkuh had taken power in Egypt. Saladin had given it to Shirkuh's son, and couldn't hand it back without losing prestige within his own family. A battle was now inevitable.
Saladin had a good defensive position, on two hills known as the Horns of Hamah. The armies of Aleppo and Mosul attacked Saladin on the hills, and at first Saladin's men were hard-pressed.
This changed when Saladin's reinforcements reached the field (presumably Saladin knew how close they were when he chose to fight). The force from Aleppo and Mosul was then trapped between Saladin's two forces and the battle turned into a rout.
Saladin had ordered his men to make sure that there was an escape route for his opponents. His long term plan was to take over both cities, so he would need the survivors of the battle to fight in his armies. The defeated army is said to have been pursued back to the gates of Aleppo, but the city wasn't threatened.
The defeated army had been commanded by Izz al-Din Masud, whose leadership appears to have been unimpressive. Saladin is reported as describing him as 'either the bravest of men or else he knows nothing of war'.
Saladin imposed surprisingly mild terms after his victory. Aleppo kept its independence, and as-Salih was recognised as its king. Political prisoners at Aleppo were to be released and the city was to support Saladin in any war against the Franks.
In return Saladin was recognised as an independent monarch in Egypt and Damascus, and kept Homs, Hamah and Baalbek. His new titles were officially acknowledged by the caliph in Baghdad.
This settlement only lasted for a few months. Saif-ad-Din hadn’t been involved in the defeat, and he convinced the authorities at Aleppo to join in another campaign against Saladin. Once again Saladin won a significant victory, this time at Tall al-Sultan in April 1176. He then moved on to secure his position at Aleppo, leaving only Mosul as an active opponent in Syria.