Ferdinand annexed some of his conquests directly into the Crown of Castile, and others were initially received and organized as vassal states under Muslim governors (e.g. Alicante, Niebla, Murcia), although they too were eventually permanently occupied and absorbed into Castile before the end of the century (Niebla in 1262, Murcia in 1264, Alicante in 1266). Outside of these vassal states, Christian rule could be heavy-handed on the new Muslim subjects. The range of Castilian conquests also sometimes transgressed into the spheres of interest of other conquerors. Thus, along the way, Ferdinand III took care to carefully negotiate with the other Christian kings to avoid conflict, e.g. the treaty of Almizra (26 March 1244) which delineated the Murcian boundary with James I of Aragon.
Ferdinand annexed some of his conquests directly into the Crown of Castile, and others were initially received and organized as vassal states under Muslim governors (e.g. Alicante, Niebla, Murcia), although they too were eventually permanently occupied and absorbed into Castile before the end of the century (Niebla in 1262, Murcia in 1264, Alicante in 1266). Outside of these vassal states, Christian rule could be heavy-handed on the new Muslim subjects. The range of Castilian conquests also sometimes transgressed into the spheres of interest of other conquerors. Thus along the way, Ferdinand III took care to carefully negotiate with the other Christian kings to avoid conflict, e.g the treaty of Almizra (26 March 1244) which delineated the Murcian boundary with James I of Aragon.