 Haldreyn was an original member of Kesva an Taves Kernewek and is a bard of the Gorseth Kernow, appointed in 1966.Haldreyn was the editor of "Gorsedd Poems" in 1983 (Truran).He was the compiler of Cornish Dictionary Supplement "Geryow Dyvers" in 1995 (Agan Tavas).