Millward studied at Cathays High School in Cardiff and then the University College of South Wales, before becoming a lecturer.[3] He married Silvia Hart, with whom he had two children: Llio, an actress and singer, and Andras, an author and martial arts trainer, who died in October 2016.[2]
Millward also served as Plaid's spokesperson on water policy in which role he advocated non-violent direct action against the construction of new reservoirs.[6] In 1976, he was libelled by Willie Hamilton, who claimed that he had been involved in terrorist activities while he tutored Charles; he received £1,000 in a settlement.[7]
Millward subsequently focused on his career as an academic, lecturing in Welsh at Aberystwyth. In the early 1980s, he supported Gwynfor Evans' successful campaign for a Welsh language television station.[8] In 2003, he launched a campaign for a centre to commemorate Dafydd ap Gwilym.[9]
In popular culture
His autobiography, Taith Rhyw Gymro, was published in 2015.[10]
He was played by Mark Lewis Jones in the Netflix series The Crown where he is shown teaching the Prince of Wales Welsh.[2] The episode entitled “Tywysog Cymru” (Prince of Wales) was praised for using the Welsh language in much of its dialogue, and was described as "incredibly useful" in promoting Welsh around the world.[11]