Four hundred and forty letters, 1923-1996, addressed to Mary or Gerald Casey, consisting of (i) one hundred and forty-seven letters, 1923-1972, to Mary Casey from correspondents including her grandmother Mary Jane Penny (23), 1923-1931, Gertrude Shackleton (10), 1944-1969, Valentine Ackland (54), 1966-1969 (mainly 1969), Monica Blake (10), 1939-1964, Patrick Casey, her brother-in-law (2), 1953-1956, Nellie S. Hounsell (5), 1945-1955, her grandfather Rowland Penny (2), 1931-1932, Barbara Kerr (1), 1973, and Vera Wainwright (2), 1956; (ii) seventy-six letters, 1939-1996, to Gerard Casey from the Powys family: John Cowper Powys (6), 1939-1949, Marian Powys Grey (1), [?1965], Katie Powys (26), 1946-1962, William Powys (14), 1946-1969, Lucy Penny (10), 1945-1960, Alyse Gregory (3), 1951-1962, Phyllis Playter (6), 1947-1971, Rose Dyer (1), 1986, Eleanor Walton (2), 1986, 1996, Peter Powys Grey (2), 1969 and [n.d.], Anthony (Tony) Dyer (1), 1986, Gilfrid Powys (3), 1986, and Mary Barham Johnson (1), 1986; and (iii) two hundred and seventeen letters, 1943-1996, to Gerard Casey from other correspondents including his mother Margaret Casey (156, mainly addressed to him and Mary, with eight addressed to Mary only), 1943-1975, John Redwood Anderson (5), 1946-1962, Timothy Hyman (3), 1975-1985, Jeremy Hooker (4), 1972-1986, Glen Cavaliero (5), 1974-1987, Kathleen Raine (10), [1970s]-1986, Kim [Taplin] (2 postcards), 1986 and [n.d.], Roland Mathias (2), 1976, Alan Clodd (1), 1975, Iorwerth Peate (1), 1974, Jack Clemo (1), 1986, Oliver [Marlow Wilkinson] (2), 1986-1987, Rosemary Manning (1), 1975, G[eorge Richard] Wilson-Knight (3), 1971-1977, David Blamires (1), 1972, and Gertrude Shackleton (2), [?1973], 1986.