In the early days of the Church, the Christians assembled for prayer and the Eucharistic celebration in ordinary rooms as was "the upper room" where, after Christ's ascension, the apostles and his other male and female followers and his mother "joined in continuous prayer" (Acts 1:12-14). The early Christians prayed also in the temple of Jerusalem, but met in their homes for 'the breaking of bread' (Acts 2:46)

After the restoration of religious freedom to Christians by Emperor Constantine, public assembly for divine worship became possible and places of worship were needed. Just as in other older religions, there were special buildings, that is temples, exclusively for religious worship, so the Christians too began to have in each locality a building for worship, which was called 'house of prayer', 'Lord's house', oratory or Church. It was from about the beginning of the 4th century that the term 'basilica' began to be applied to some of the Churches.

Basilica was the name given to large Roman halls built for secular purposes, mainly for transacting business or administering justice. They were often of rectangular form with interior colonnades and an apse at on end or at each end. The oldest known as basilica was built about the year 180 B.C. by the elder Cato (234-149 B.C.). Several basilicas, generally near forums, were built before A.D. 300, both in Rome and in the colonies.

When Constantine gave religious freedom and state patronage to Christians, some of the basilicas built for civic purposes passed into Christian hands and were converted to places of Christian worship. The term 'basilica' remained attached to them. The basilica of St. John Lateran, cathedral Church of the Bishop of Rome and "mother of all the Churches", was itself built over a former civil basilica.

The Christians also built new places of worship architecturally modelled after basilicas but adapted for Christian needs. These too were called 'basilicas'. Later, not only Churches that were large and architecturally imposing were also called basilicas. The term basilica thus assumed a special dignity and began to be used for Churches that has risen to prominence for one reason or another.

The larger and better known of the basilicas of Rome are St. John Lateran, St. Peter's, St. Mary Major, St. Paul's outside the walls, St. Lawrence's and St. Agnes'.

The Church today may officially bestow the title of basilica on a Church anywhere in the Catholic world for such reasons as its being ancient and venerable, a renowned shrine, or its national or international importance. This is an official recognition by the Church of the noteworthy position held by the Church in the religious life of the faithful. At the same time, by giving it a status and dignity, the Church encourages the faithful towards a more fruitful use of it.