The ubiquitous class 66 loco first emerged on to the UK freight scene in 1998, with many getting their first close-up look at these engines at the Open Day at Toton in August that year. 2023 sees the twenty-fifth anniversary of the class in operation in the UK. Since pioneer 66001 went on display at the, then, EWS-owned depot back in 1998, over 400 of these machines have seen service in the UK through all the major railfreight operators. This book looks at the rapid cascade of these locomotives across the UK in that twenty-five year period. The class 66’s area of operation extends from the China Clay traffic in the south-west of England through to services to both Fort William and Inverness in the Scottish Highlands. It is also a celebration of the variety of traffic on offer to the observer of our railways today.