Balearic Islands having partitioned his domains between his sons in his will. The will created a new Kingdom of Mallorca from the Balearic islands and the mainland counties of Roussillon or Montpellier, which was left to his son James II. However, the terms of the will specified that the new kingdom be a vassal state to the Kingdom of Aragon, which was left to his older brother Peter. Chafing under the vassalage, James joined forces with the Pope Martin IV and Philip III of France against his brother in the Aragonese Crusade, leading to a 10-year Aragonese occupation before the islands were
Balearic Islands province of Hispania Tarraconensis, of which province they formed the fourth district, under the government of a praefectus pro legato. An inscription of the time of Nero mentions the PRAEF. PRAE LEGATO INSULAR. BALIARUM. (Orelli, No. 732, who, with Muratori, reads "pro" for "prae.") They were afterwards made a separate province, called Hispania Balearica, probably in the division of the empire under Constantine. The two largest islands (the Balearic Islands, in their historical sense) had numerous excellent harbours, though rocky at their mouth, and requiring care in entering them (Strabo, Eustath.; Port Mahon is one of the finest harbours in