The Basilica of the Holy Trinity of the Chancellor, commonly known as "The Mansion", is one of the oldest churches in the city of Palermo. Founded in 1191 by Norman Chancellor Matthew of Aiello and annexed the adjacent Cistercian abbey, it houses the remains of Roger de Hauteville. In 1197 it was awarded the Order of the Teutonic Knights who, as a result of donations, it increased the property and prestige. Over the centuries, the Basilica underwent several changes, such as the building of a Baroque portal, still present, and the integration of a Neoclassical porch, then demolished during the restoration by Valenti, in 1920. The present appearance of the building, with an adjoining cloister of the twelfth century, is presented as a particular example of Arab-Norman art, with pointed windows embedded and the reason of the intertwined arches, reproduced in the apse, typical of the period. Inside, almost bare, it preserves a marble triptych of the sixteenth century and a "Crucifixion" by an unknown fifteenth century author, preserved in the adjacent oratory.