The Fleet line through central London was first proposed in 1965, taking over the Bakerloo line's Stanmore branch at Baker Street and then running via Fleet Street to Lewisham. To simplify planning the construction was divided into stages, and the first stage from Baker Street to Charing Cross had all the necessary approvals by 1971. Work began the following year and tunnelling had been completed in 1976. After the line had been renamed the Jubilee line in honour of Queen Elizabeth's Silver Jubilee in 1977, the line opened in April 1979 using trains that had been running on the Bakerloo line.