Only the grand Westminster Hall and the crypt dating to the times of William II survived of the Royal Palace, an old palace built in the 11th century for King Edward the Confessor. In the 13th century King Henry III decreed to attach a new hall to the remaining structures, where knights and town representatives could gather to jointly decide on pressing matters of the kingdom - in sum, to talk ("parler"). That was the creation of the first Parliament, whose members held sessions in St. Stephen Chapel.
Westminster Palace survived the Great Fire of London in 1666, but burned down almost completely in 1834. In the Victorian times the palace was replaced by the majestic Neo-Gothic Parliament: its construction had been so arduous that one of the architects, Augustus Pugin, lost his mind in the process. St. Stephen Chapel was replaced by a wide passage, decorated with paintings and sculptures. The total length of offices, corridors, halls and lobbies now adds up to 3 kilometres!