Llythyrau, 1940-1996, oddi wrth bedwar ar ddeg o unigolion blaenllaw ym mywyd Cymru a ohebai'n gyson â Gwynfor Evans yn trafod yn bennaf materion gwleidyddol, yn fwyaf amlwg datblygiad a gweithgareddau Plaid Cymru. Ceir hefyd o fewn y llythyrau gyfeiriadau at ddiddordebau academaidd, ysgolheigaidd a diwylliannol yr awduron ynghyd â thrafod eu bywydau personol a theuluol./ Letters, 1940-1996, from fourteen individuals prominent in Welsh life who corresponded regularly with Gwynfor Evans discussing mainly political matters, most especially the development of Plaid Cymru and its activities. The letters also contain references to the academic, scholarly and cultural interests of their authors, together with some discussion of their personal and family lives.