Lateran Palace is also known as the Apostolic Palace, Lateran Basilica or Palace of the Popes. It was the official residence of the popes for centuries before they moved to the Vatican Palace. But this building still has great historic and religious significance as it hosts important papal functions. Additionally, it houses the Vatican Library and its Art Collection, which make it one of the world's most significant museums. In the past, the palace was also the center of the Holy Roman Empire and home to the original Lateran Councils. Some other synonyms for the Lateran Palace are the Palace of the Holy Apostles or the Lateran Apostolic Palace.