- What is a basilica? How many basilicas are there?
A basilica is a church that has specific detication or ceremonial rights, as given by the Pope (see the excerpt below). There are over a thousand baslicas around the world. A complete list of them can be found here: http://en.wikipedia.org/wiki/List_of_basilicas
An excerpt from the Catholic Encyclopedia:
"Basilica" in the canonical sense
Basilica, as a term used by canon lawyers and liturgists, is a title assigned by formal concession or immemorial custom to certainmore important churches, in virtue of which they enjoy privileges of an honorific character which are not always very clearlydefined. Basilicas in this sense are divided into two classes, the greater or patriarchal, and the lesser, basilicas.
To the former class belong primarily those four great churches of Rome (St. Peter's, St. John Lateran, St. Mary Major, and St. Paul-without-the-Walls), which among other distinctions have a special "holy door" and to which a visit is always prescribed as one of the conditions for gaining the Roman Jubilee. They are also called patriarchal basilicas, seemingly as representative of the great ecclesiastical provinces of the world thus symbolically united in the heart of Christendom.
- St. John Lateran is the cathedral of the pope, the Patriarch of the West.
- St. Peter's is assigned to the Patriarch of Constantinople,
- St. Paul's to the Patriarch of Alexandria,
- St. Mary Major to the Patriarch of Antioch.
- St. Lawrence-outside-the-Walls is also reckoned as a greater basilica because it is specially attributed to the Patriarch ofJerusalem.
Moreover, a few other churches, notably that of St. Francis at Assisi and that of the Portiuncula, have also received theprivilege of ranking as patriarchal basilicas. As such they possess a papal throne and an altar at which none may say Massexcept by the pope's permission.
The lesser basilicas are much more numerous, including nine or ten different churches in Rome, and a number of others, such as the Basilica of the Grotto at Lourdes, the votive Church of the Sacred Heart at Montmartre, the Church of Marienthal in Alsace, etc. There has been a pronounced tendency of late years to add to their number. Thus the "Acta Apostolicae Sedis" for 1909 contain six, and the "Acta" for 1911 eight, such concessions.
We, by our apostolic authority . . . erect (such and such a church) to the dignity of a lesser basilica and bestow upon it all the privileges which belong to the lesser basilicas of this our own cherished city.
These "privileges", besides conferring a certain precedence before other churches (not, however, before the cathedral of any locality), include the right of the conopaeum, the bell, and the cappa magna. The conopaeum is a sort of umbrella (also calledpapilio, sinicchio, etc.), which together with the bell is carried processionally at the head of the clergy on state occasions. Thecappa magna is worn by the canons or members of the collegiate chapter, if seculars, when assisting at Office. The form of theconopaeum, which is of red and yellow silk, is well shown in the arms of the cardinal camerlengo (see vol. VII, p. 242, coloured plate) over the cross keys.
The Catholic Encyclopedia has a great entry on basilicas: http://www.newadvent.org/cathen/02325a.htm