The title of Admiral of Castile was created by King Ferdinand III the Saint in 1247 for the successful Siege of Seville, appointing Ramón de Bonifaz to that position.
After the conquest of Seville, this title was covered with great authority, power and pre-eminence, which are specified by Alfonso X the Wise in the Siete Partidas.
The Admiral resided in Seville, because the Royal Shipyards were constructed there and it was the place where the fleets were armed and organized and where the special maritime court was also located.
Among the multiple attributions and powers of the admiral, they included having a voice and casting vote in the Council of Castile.
The Admiral became a palace man and stopped participating personally in the naval wars, while the Castilian navy was transformed, replacing the royal galleys with private sailing ships, hired for each campaign.