The Council of Castile (), known earlier as the Royal Council (), was a ruling body and key part of the domestic government of the Crown of Castile, second only to the monarch himself. It was established under Queen Isabella I in 1480 as the chief body dealing with administrative and judicial matters of the realm. With the 1516 ascension of King Charles I (later Holy Roman Emperor Charles V) to the throne of both Castile and Aragon, the Royal Council came to be known as the Council of Castile because Charles was king of many dominions other than Castile, while the Council retained responsibility only over Castile. During periods in which there was no monarch, an absent monarch, or an incompetent monarch, the Royal Council would rule as a regency council in his place. The Council weakened in the 19th century, where it was abolished and re-established several times before being dissolved permanently. History Origins The earliest form of the Royal Council was created at the end of the fourteenth century in 1385 by King John after the disaster at the Battle of Aljubarrota. It consisted of 12 members, four from each of the clergy, the cities, and the nobility. In 1442 the nobility increased its influence on the council, adding many nobles as titular members of the council. Sixty became the new number of members. Under the Catholic Monarchs: Centralization This council was rather ineffective and the Catholic Monarchs, King Ferdinand II of Aragon and Isabella I, sought to change it in their drive to centralize the country and bring it more firmly in line with national interests rather than the nobles. In 1480, they passed the Act of Resumption at the Cortes of Toledo. This act would allow Ferdinand and Isabella to directly appoint bureaucrats, rather than letting the independent and erratic nobles rule. The Royal Council would control both a royal army and manage tax disputes, which would place nobles more securely under the control of the Crown. The new composition of the reformed Council was a president, a treasurer, a church prelate, three caballeros (often minor nobility), and between eight and ten letrados (lawyers or jurists). These were Council's chief duties: To advise the Crown on matters of appointments, both military and civil Until the creation of the Council of the Indies, to supervise works, projects, expeditions, and colonizations commissioned by the Castilian government, in