[2] Alfonso's father died when he was two years old and he remained under the guardianship of his cousin, William Jordan, Count of Cerdagne, until he was five.

His ascendancy was, according to one commentator, an unmixed good to the country, for during a period of fourteen years art and industry flourished.

In 1141 King Louis VII of France pressed the claim of his wife, Eleanor of Aquitaine, granddaughter of Philippa, even besieging Toulouse, but without result.

[10] That same year Alfonso Jordan was again in Spain, making a pilgrimage to Saint James of Compostela, when he proposed a peace between the king of León and García Ramírez of Navarre, which became the basis for subsequent negotiations.

In 1145, Bernard of Clairvaux addressed a letter to him full of concern about a heretic named Henry in the diocese of Toulouse.

He died at Caesarea,[14] which was followed by accusations of poisoning, levelled against either Eleanor of Aquitaine or Melisende of Jerusalem,[14] who may have wanted to eliminate him as a rival to her brother-in-law Count Raymond II of Tripoli.