Peter Trudgill has suggested that a number of the processes involved in new-dialect formation may be of a widespread or universal type. Multicultural London English (MLE) is a new dialect that emerged in a different and more complex sociolinguistic situation than those considered previously, so it provides an opportunity to further consider the extent to which the processes are widespread or universal. I argue that the characteristic features of MLE emerged as a result of dialect mixture, including traditional London English, colonial and creole-influenced varieties of English, and many different interlanguage varieties of English. Some MLE features confirm the relevance of the levelling of minority forms, and perhaps also of simplification. There is also evidence of drift. Above all, their emergence confirms the importance of linguistic accommodation in face-to-face interactions. In this, as for so many sociolinguistic issues, Peter Trudgill was right!