Year 1224 (MCCXXIV) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire Spring – Battle of Poimanenon: Byzantine forces under Emperor John III (Doukas Vatatzes), ruler of Nicaea, defeat the Latin army under the brothers Alexios Laskaris and Isaac Laskaris. They begin a revolt and decide to aid the request of Emperor Robert I of Courtenay. The two armies meet at Poimanenon, south of Cyzicus in Mysia, near Lake Kuş (Bird Lake). In the ensuing battle, John III achieves a decisive victory; among the captives taken are the two Laskaris brothers, who are blinded. The victory opens the way for the recovery by the Byzantines of most of the Latin possessions in Asia Minor. December – Theodore Komnenos (Doukas), ruler of the Despotate of Epirus, captures Thessaloniki – beginning the de facto Byzantine Empire of Thessalonica. Later, Theodore Komnenos has crowned Byzantine emperor but is not recognized as such by the rest of the Greek or Latin population. Europe February – King Ferdinand III (the Saint) announces his intention to resume the Reconquista against the realm of the Almohad Caliphate. Caliph Yusuf II al-Mustansir dies and is succeeded by Abu Muhammad al-Wahid, but in Al-Andalus, two competing pretenders also claim their rights to the throne: Abu Muhammad Ibn al-Mansur al-Adil in Seville and Abu Muhammad abu Abdallah al-Bayyasi in Córdoba. The chronic political instability on the Almohad site allows Ferdinand to begin his campaign victoriously in October, with the capture of Quesada in Spain. May 5 – King Louis VIII (the Lion) declares war on King Henry III of England. He allies himself with Hugh X of Lusignan and invades first Poitou and then Northern Gascony. The English forces in Poitou are under-strength and lack support from the Poitevin nobles; as a result, the province quickly falls into French hands by the end of June. September – Abdallah al-Adil (the Just), governor in Al-Andalus, challenges the Almohad throne and captures Seville. He marches to Marrakesh to confront Abu Muhammad al-Wahid. Abdallah seizes the royal palace and deposes Muhammad al-Wahid, who is murdered by strangulation. Livonian Crusade: The Livonian Brothers of the Sword defeat the Estonians and reconquer the captured strongholds on the Estonian mainland. With the surrender of the Tartu stronghold, only the islands of Saaremaa and Muhu remain under Estonian control. England Spring – Falkes de