The Mercedes-Benz Citaro first entered service in London during 2002, in both rigid and articulated forms. Over the coming years, the articulated type was used to convert a number of central London services from Routemaster and double-deck operation. A change of policy saw the demise of the articulated type, the last of which were operating on the 207 in 2012. However, this did not spell the end of the Citaro in London, with a handful of small batches being purchased by various London operators on a handful of routes in south-east London. First London also took three hydrogen Citaros on trial on the RV1. This book provides a potted history of the Citaro in London service.