One of the most distinctive-looking locomotives built for the railways of Britain, the A4 class of the London & North Eastern Railway was introduced in 1935 for a special train to honour King George V's Silver Jubilee - silver-painted coaches and locomotives bearing names such as Silver Fox and Silver Link. Many later engines were named after birds, honouring Sir Nigel Gresley's keen interest, most famously Mallard. 

Locomotive 4498 was built in 1937 and was originally to have been called Bittern until someone noticed that this would be the 100th Gresley-designed Pacific and so it was decided to name her after her designer (a later locomotive inherited the name Bittern and has also been preserved). Following a naming ceremony at Marylebone Station on 26th November, she entered service. The locomotive was mainly based at London King’s Cross with a spell at Grantham during World War II.

The locomotive was briefly re-numbered as No. 7 before becoming 60007 when the LNER was merged into British Railways. The ‘Stevenson Locomotive Society Special’ on the 23rd May 1959 was the first train in the UK with a booked or advertised schedule of over 100mph and on that trip 60007 set the official post-war speed record for steam traction of 112 mph. In 1963 the locomotive moved to Scotland and was used on express services between Aberdeen and Glasgow.

In preservation she has most recently worn the British Railways "Caledonian Blue" livery used for a short time in the late 1940s on the fastest express locomotives - other liveries worn historically by the locomotive include LNER "Garter Blue", wartime plain black and British Railways "Brunswick Green"

Sir Nigel Gresley is owned and preserved by the Sir Nigel Gresley Locomotive Trust Ltd. The ‘boiler ticket’ on Sir Nigel has expired and the locomotive was withdrawn from service in September 2015. The overhaul is well underway in public view at National Railway Museum, York with the boiler being serviced in Llangollen.