No, some basilicas may have the remains of a saint present but it is not a requirement to be named as a basilica.
Saint Peter's is the "headquarters" church of Catholicism. It contains the earthly remains of Saint Peter and many other popes. It also has many fine works or art. Saint Peter's marks the place were Saint Peter is said to have been martyred.
The remains of Saint Valentine were removed from the Catacombs of Saint Valentine in Rome and placed in a basilica in Terni, Italy in 273 AD. Some relics attributed to Saint Valentine were also claimed by the Franciscan church in the Church of St. Praxedes in Rome.
The purported relics of the Apostle Andrew are kept at the Basilica of St Andrew in Patras, Greece; the Duomo di Sant'Andrea, Amalfi, Italy; St Mary's Roman Catholic Cathedral, Edinburgh, Scotland; and the Church of St Andrew and St Albert, Warsaw, Poland. There are also numerous smaller reliquaries throughout the world.
The relics that reside in the Venice Cathedral, also known as St. Mark's Basilica, primarily belong to Saint Mark the Evangelist. According to tradition, his remains were brought to Venice from Alexandria, Egypt, in the 828 AD. The basilica is dedicated to him and is known for its stunning architecture and mosaics, reflecting the city's rich history and connection to maritime trade. Saint Mark is considered the patron saint of Venice, and his relics play a significant role in the city's cultural and religious identity.
The original Saint Peter's was badly in need of repair and also was not large enough to meet the needs of a growing Church membership.
St. Peter's Basilica used for Mass like any Catholic church. Of course it is most well-known for for the papal liturgies which take place there. It should be noted however, that St. Peters is NOT a cathedral.
Parts of St. Andrew are scattered all over Europe. Relics are kept at the Basilica of St Andrew in Patras, Greece; the Duomo di Sant'Andrea, Amalfi, Italy; St Mary's Roman Catholic Cathedral, Edinburgh, Scotland; and the Church of St Andrew and St Albert, Warsaw, Poland. There are also numerous smaller reliquaries throughout the world.
Donato Bramante was an Italian architect who was most famous for his plans for Saint Peter's Basilica, but he is also known for his structure known as the Tempietto, commissioned by Pope Julius II to be a sanctuary upon the spot where Saint Peter was crucified.
The most obvious is Saint Peter's Basilica, the largest church in the world. There is also the Apostolic Palace which includes the famous Sistine Chapel. The Vatican also has a number of museums.
Parts of St. Andrew are scattered all over Europe. Relics are kept at the Basilica of St Andrew in Patras, Greece; the Duomo di Sant'Andrea, Amalfi, Italy; St Mary's Roman Catholic Cathedral, Edinburgh, Scotland; and the Church of St Andrew and St Albert, Warsaw, Poland. There are also numerous smaller reliquaries throughout the world.
St. Peters Basilica is located in Vatican City, Rome.Vatican City is also the worlds smallest country.Find out more about St. Peter's Basilica at http://vaticanart.net/st-peters-basilica-architecture
St. Andrew's body is scattered all over Europe. Relics of the Apostle Andrew are kept at the Basilica of St. Andrew in Patras, Greece; the Duomo di Sant'Andrea, Amalfi, Italy; St. Mary's Roman Catholic Cathedral, Edinburgh, Scotland; and the Church of St. Andrew and St. Albert, Warsaw, Poland. There are also numerous smaller reliquaries throughout the world. For specific locations in each of the above churches you would have to consult with a local parishioner at the church in question.