The 1st Infantry Regiment "Los Patricios" (Regimiento de Infantería 1 "Los Patricios") is the oldest and one of the most prestigious regiments of the Argentine Army. The title is often shortened to the Patricians' Regiment (Regimiento de Patricios). Since the 1990s the regiment has been designated as air assault infantry. It is also the custodian of the Buenos Aires Cabildo, the welcoming party for visiting foreign dignitaries to Argentina and the escort and honor guard battalion for the City Government of Buenos Aires. Since 22 September 2010, the Regiment's headquarters building has been a National Historical Monument following a declaration by the Argentine government on the occasion of the country's bicentennial year.