The heyday of the line was between 1923, when the GCR was absorbed into the London and North Eastern Railway (LNER) and 1948, when the LNER was nationalised to form the British Rail Eastern Region. As a result, many prestigious locomotives, such as "Flying Scotsman", "Sir Nigel Gresley", and "Mallard" which ran on the East Coast Main Line, were frequent visitors to the line. Special trains ran on the line to destinations such as Scotland. The station's busiest use came after the construction of Wembley Stadium in 1923, when it was used to contain large crowds wishing to see the FA Cup Final. Special services ran from Marylebone to the British Empire Exhibition at Wembley Park the following year.