Queen of Jerusalem (1225-1228), coming to the throne as a minor in succession to her mother, Maria of Montferrat. Isabella was nominal ruler until her death in 1228, although power was exercised on her behalf by her father, John of Bri- enne, and then her husband, Frederick II, Holy Roman Emperor.
Nothing is known of Isabella’s early life, but in March 1223 it was agreed that she should marry Frederick in order to secure his support for the kingdom of Jerusalem. The wedding took place by proxy in Acre (mod. ‘Akko, Israel) in 1225, and Isabella was then crowned. In August she sailed for Europe, accompanied by senior prelates and barons from the realm, and the marriage was solemnized on 9 November 1225 in Brindisi. Isabella remained in the West and died soon after the birth of her son, Conrad (IV), heir to the throne of Jerusalem, in April 1228.