The Brothers' Quarrel () was a war of succession within the Árpád dynasty between Emeric, the King of Hungary, and his younger brother, Andrew, Duke of Slavonia. It lasted from 1197 to 1203, covering almost the entire reign of Emeric. The conflict had a significant impact on the development of the 13th-century society and political system in the Kingdom of Hungary.
Background
The illustrious Béla III ruled Hungary from 1172 to 1196. His first wife was Agnes of Antioch, the mother of all of his children. Their first child, a boy named Emeric, was born in 1174. Andrew, the second son of Béla III and Agnes, was born around 1177. Béla and Agnes had two other sons, Solomon and Stephen. One of them was still alive in early 1198.
In order to ensure the uninterrupted succession to the Hungarian throne, Béla III decided to crown his eldest son during his lifetime. Emeric was crowned king while still a child by Nicholas, Archbishop of Esztergom, on 16 May 1182. This method was unusual within the Árpád dynasty, which was plagued by many struggles for the throne throughout its history. After Solomon (1057) and Stephen II (1105), Emeric was the third heir to be crowned King of Hungary during the lifetime of his father, the reigning monarch. Béla III appointed Emeric to administer Croatia and Dalmatia around 1193 or 1194. Historian Gyula Kristó claimed Emeric's coronation in 1182 was forced against his father by the most powerful barons of the realm. In contrast, Szabados argued that Emeric did not independently issue a royal charter and did not have his own court. Bálint Hóman claimed that Béla III crowned his eldest son as co-monarch in the manner of the Byzantine emperors. Croatian historian Ferdo Šišić believed that Emeric was crowned as King of Croatia and Dalmatia in 1194, separately.
Following Béla III's successful invasion of the Principality of Halych in 1188, his youngest, son Andrew, was installed as Prince of Halych. His nominal reign was unpopular and the loyal boyars expelled Andrew and his retinue from the principality in August 1189 or 1190. Upon his return to Hungary, Andrew did not receive a new duchy from his father, who only gave him some money, as well as some fortresses and estates in Slavonia. On his deathbed, Béla III, who had pledged to lead a crusade to the Holy Land, ordered Andrew to fulfill his vow. Béla III died on 23 April 1196, and Emeric succeeded him as King of Hungary without opposition.
Dynastic conflict
Andrew's first conspiracy (1197)
Andrew used the funds that he inherited from his father to recruit supporters among the Hungarian lords. It is plausible that he demanded from his brother to install him as Duke of Slavonia, which, by the second half of the 12th century, increasingly became the traditional title of heir to the throne. Andrew also formed an alliance with Leopold VI, Duke of Austria, and plotted against Emeric. The king learned of the conspiracy and filed a complaint against his brother to Pope Celestine III, who threatened excommunication for those who supported the duke against Emeric. The united troops of Andrew and Leopold attacked and routed the Hungarian royal army at Mački (Macsek), Slavonia, in the late autumn of 1197. Under duress, King Emeric might have gave Croatia and Dalmatia to Andrew as an appanage. Regardless, a series of privilege letters in favor of Dalmatian coastal cities and ecclesiastical institutions prove that King Emeric intended to exercise his royal rights as King of Croatia and Dalmatia, whether Andrew held the ducal title or not.