Bela III of Hungary (Hungarian III. Béla, Slovak: Belo III), born in 1148, was King of Kingdom of Hungary circa 1172-1196. He was the son of King Geza II of Hungary and Euphrosyne (daughter of Grand Duke Mstislav of Kiev). As a boy he was sent to Constantinople to be educated in the court of the Emperor. Bela III succeeded his brother Stephen III of Hungary and was crowned under the influence of his father-in-law, the Byzantine Emperor Manuel I Comnenus. Bela III married:

• Maria Comnena, daughter of Emperor Manuel I Comnenus, with no issue. They were engaged in 1163, separated in 1169.
• Agnes de Chatillon (1154-1184), daughter of Raynald of Chatillon and Constance of Antioch (joint princes of Antioch). They married in 1172 with issue:

1. King Emeric of Hungary (1174-1204)
2. Margareta of Hungary (1175-1223), married Emperor Isaac II Angelus and Boniface of Montferrat.
3. King Andrew II of Hungary (1176-1235)
4. Soloman, died young
5. István, died young
6. Konstancia of Hungary (1180-1198), married King Otakar II of Bohemia

• Marguerite Capet, daughter of King Louis VII of France, married in 1186, with no issue.

Through his son Andrew II, he is the ancestor of Edward III of England through Isabella of France. He is therefore an ancestor to the present-day British royal family including Elizabeth II of the United Kingdom of Great Britain and Northern Ireland.