The phenomenon of /l/-darkening has been a subject of linguistic interest due to the remarkable amount of contextual variation it displays. Although it is generally stated that the light variant occurs in onsets (e.g. leap) and the dark variant in codas (e.g. peel), many studies report variation in different morphosyntactic environments. Beyond this variation in morphosyntactic conditioning, different dialects of English have been reported as showing highly variable distributions. These descriptions include a claimed lack of dis- tinction in the North of England, a three-way distinction between light, dark and vocalised /l/ in the South-East, and a gradient continuum of darkness in American English. This paper presents ultrasound tongue imaging data collected to test dialectal and contextual descriptions of /l/ in English, providing hitherto absent instrumental evidence for different distributions. Data from speakers of RP, Manchester, Essex and American English show that dialectal diversity has been vastly underestimated in the existing literature on /l/- darkening. The wide range of dialectal diversity, for which this paper provides only a small subset, shows a great deal of orderliness when paying due consideration to the diachronic evolution of variable phonological processes.