Ferdinand became jure uxoris King of Castile in 1474. When Ferdinand succeeded his father as King of Aragon in 1479, the Crown of Castile and the various territories of the Crown of Aragon were united in a personal union, creating for the first time since the 8th century a single political unit, referred to as España (Spain). "Los Reyes Católicos" started policies that diminished the power of the bourgeoisie and nobility in Castile, and greatly reduced the powers of the Cortes (General Courts) to the point where they became rubber-stamps for the monarch's acts. They also brought the nobility to their side. In 1492, the Kingdom of Castile conquered the last Moorish state of Granada, thereby ending Muslim rule in Iberia and completing the Reconquista. 16th century On Isabella's death in 1504 her daughter, Joanna I, became Queen (in name) with her husband Philip I as King (in authority). After his death Joanna's father was regent, due to her perceived mental illness, as her son Charles I was only six years old. On Ferdinand II's death in 1516, Charles I was proclaimed as king of Castile and of Aragon (in authority) jointly with his mother Joanna I as the Queen of Castile (in name). As the first monarch to reign over both Castile and Aragon, Charles I may be considered as the first operational King of Spain. Charles I also became Charles V of the German-Roman Empire in 1519. Government: municipal councils and parliaments As with all medieval kingdoms, supreme power was understood to reside in the monarch "by the grace of God", as the legal formula explained. Nevertheless, rural and urban communities began to form assemblies to issue regulations to deal with everyday problems. Over time, these assemblies evolved into municipal councils, known as variously as ayuntamientos or cabildos, in which some of the inhabitants, the property-owning heads of households (vecinos), represented the rest. By the 14th century these councils had gained more powers, such as the right to elect municipal magistrates and officers (alcaldes, speakers, clerks, etc.) and representatives to the parliaments (Cortes). Due to the increasing power of the municipal councils and the need for communication between these and the King, cortes were established in the Kingdom of León in 1188, and in Castile in 1250. Unlike other kingdoms, Castile didn't have a permanent capital (neither did Spain until the 16th Century), so the cortes were celebrated