Built between 1426-1434 by Mestre Huguet, the Founder's Chapel is one of the most important buildings adjacent to the monastery, it marks its character of "Royal Power". D. João I was a bastard son of D. Pedro I, desirous of asserting real power, leaving his descendants in the construction of this family Pantheon. In the central part, the conjugal tomb of the founding king, D. João I and Filipa de Lencastre. This tomb represents a type of sculpture with more detail and greater naturalism in the representation of the human figure on the south wall, from left to right are the tombs of the infants their children: D.Fernando, D.João and his wife D.Isabel de Barcelos, D. Henrique the navigator Duque de Viseu, D. Pedro Duque de Coimbra and his wife D. Isabel de Aragão. On the west façade are D. Afonso V and his wife D. Isabel of Coimbra, D. João II and his son, Prince D. Afonso.