Calle del Castillo
The street’s name is attributed either to the comunero Gregorio del Castillo, chief magistrate of Madrid in 1520, or to a supposed vanished Templar fortress on this ground.
Few streets this short hold an argument this old. The Calle del Castillo is a brief stretch between Raimundo Lulio and Eloy Gonzalo, in the Trafalgar neighborhood, laid out late, when Chamberí was already growing as the northern expansion. Its name, however, looks much further back, and there is no agreement on which castle it refers to.
One version points to a person: Gregorio del Castillo, a bachelor of arts elected chief magistrate of Madrid in 1520, during the revolt of the Comunidades of Castile, and one of the leaders of the town that rose against Charles I.
The other prefers a building. It is conjectured that this ground belonged to the Order of the Temple and that a Templar fortress stood here; once gone, its ruins would have survived long enough for the locals to call the spot “the Castle”. The sign leaves both readings open.