The AEC Regal IVs and Regent IIIs, or to give them their class prefix letters RFs and RTs, are among the most revered buses to have served London over the years. The RFs were maids of all work and were tailored for private hire, Green Line coach work and ordinary stage bus work in both the central and country areas. The first of the type were introduced in October 1951 and a total of 700 vehicles were built for the London Transport Executive. They replaced virtually all the other types of single-deckers then operating in the metropolis. The RT was first introduced to service in 1939 and production ran to 151 vehicles before construction ceased in early 1942. Following the war, the Park Royal factory recommenced building the type in 1947, with the last new chassis being rolled out in 1954, taking the bonnet number RT4825. Both types soldiered on throughout the 1970s as LTE encountered severe problems with their 'OPO' replacements before both finally bowed out within a week of each other in March/April 1979. This account charts the last years of operation of both types from the mid-1970s onward, focusing on North London.