The most elaborate and up-to-date research on training interpreters in Languages of Lesser Diffusion brought together The number of foreign language speakers involved in criminal procedures has quadrupled over the last thirty years. In many of these cases, the person's native language was an LLD (Language of Lesser Diffusion): a language that has relatively few speakers in one specific location or geographical area in relation to the population as a whole. These people have the right to be addressed in their own language. The need for legal interpreters and translators of LLDs is therefore great, and still rising. Given the particular characteristics of this type of languages, specific methodologies and programmes are required for LLD interpreter training. Existing strategies in organizing training were analyzed by the TraiLLD consortium in order to test their efficiency, to improve them, and to develop alternative approaches. The result is an evidence-based set of practical recommendations, brought together in one volume.