Kenneth Hurlstone Jackson (1 November 1909 – 20 February 1991) was an English linguist and a translator who specialised in the Celtic languages. He argued that text of the Ulster Cycle of tales, written circa AD 1100, preserved an oral tradition originating some six centuries earlier and reflects Celtic Irish society of the third and fourth century AD. His Celtic Miscellany is a popular standard. In retirement, Jackson continued his work on place-names and Goidelic languages. However he suffered a stroke in 1984 that restricted his work. An obituary was published in The Times on 8 March 1991 and in the journal Nomina. Source: Wikipedia (en)