The Great Western Railway 2900 Class or Saint Class, which was built by the Great Western Railway's Swindon Works, incorporated several series of 2-cylinder passenger steam locomotives designed by George Jackson Churchward and built between 1902 and 1913 with differences in the dimensions. The majority of these were built as 4-6-0 locomotives; but thirteen examples were built as 4-4-2 (but converted to 4-6-0 during 1912/13). They proved to be a successful class which established the design principles for GWR 2-cylinder classes over the next fifty years.

The Saint class appeared in four production series built between 1905 and 1913, each of which differed in dimensions. There were also differences between members of each series in terms of the boilers used, wheel arrangement, and arrangements for superheating. Different series and individual locomotives within series were also fitted with different tenders

None of the original saints survived to preservation, so the Great Western Society purchased GWR 4900 Hall Class 4-6-0 No. 4942 Maindy Hall from Barry Scrapyard in 1974. The intention was to rebuild this Hall as a Saint, reversing the procedure where a Saint had been rebuilt as the Hall prototype. The project did not progress in the 1970s and 1980s, but finally started in earnest in 1995, by which time engineering capability in the preservation movement had greatly increased. It was also decided that the engine would be built in the original straight frame form like the first Saints instead of the later curved frame style as fitted to Maindy Hall. Following thirty years of storage and fifteen years of rebuilding work 2999 Lady of Legend made its first moves in April 2019 and was formally launched at the Didcot Railway Centre in the same month.