Editing Alphonse, Count of Poitiers (section)

== Later life ==
In 1252, on the death of his mother, Blanche of Castile, Alphonse was joint regent with [[Charles of Anjou]] until the return of Louis IX. During that time he took a great part in the campaigns and negotiations which led to the [[Treaty of Paris (1259)|Treaty of Paris]] in 1259, under which King [[Henry III of England]] recognized his loss of continental territory to [[France]] (including [[Normandy]], [[Maine (province of France)|Maine]], [[County of Anjou|Anjou]], and [[Poitou]]) in exchange for France withdrawing its support for English rebels.{{sfn|Clanchy|1983|p=274}}

[[File:Arms of Alphonse de Poitiers.svg|thumb|upright|Alphonse's [[coat of arms]] was formed of those of France (left) and Castile (right), representing his father and mother respectively: ''Per pale azure semé-de-lis or dimidiating gules semé of castles or'']]

Aside from the crusades, Alphonse stayed primarily in Paris, governing his estates by officials, inspectors who reviewed the officials' work, and a constant stream of messages.{{sfn|Petit-Dutaillis|1936|pp=299–300}} His main work was on his own estates. There he repaired the effects of the [[Albigensian Crusade|Albigensian war]] and made a first attempt at administrative centralization, thus preparing the way for union with the crown. On 8 October 1268, Alphonse had all Jews throughout his lands arrested and their property confiscated.{{sfn|Benbassa|2001|p=19}}

When Louis IX formed the [[Eighth Crusade]], Alphonse again raised a large sum of money and accompanied his brother.{{sfn|Strayer|1969|p=511}} This time, however, he did not return to France, dying while on his way back, at [[Savona]] in Italy, on 21 August 1271.{{sfn|William of Puylaurens|2003|p=122}}