Buenos Aires (English: Fair Winds) was originally called Ciudad de la
Santísima Trinidad y Puerto de Santa María del Buen Aire, "City of the Most Holy Trinity and Port of Saint Mary
of the Fair Wind".
The city name was chosen by the chaplain of Mendoza's expedition (see History, below), who was a devout follower
of the Virgine de Bonaria ("Our Lady of the Fair Winds") of Cagliari, Sardinia.
Argentines sometimes refer to the city as Capital Federal to differentiate the city from the province of the same
name. In the 1994 constitution, the city was given autonomy, hence its formal name: Ciudad Autónoma de Buenos Aires.
The abbreviations Bs. As. and Baires are sometimes used, the first one mostly in writing and the second one
in everyday speech. The city is sometimes called La Reina del Plata, that is, "The Queen of the Plata" (a reference
to the Plata river basin).