Kellas entered the diplomatic service in 1939. After the outbreak of
World War II that year, he was commissioned into the
Border Regiment, and later served with the 1st Battalion,
Parachute Regiment. He was mentioned twice in despatches. In 1948, he was sent as first secretary to
Helsingfors. From 1951 to 1952, he served as first secretary (press) at
Cairo, and during his posting was declared
persona non grata on the grounds that his activities were against the interests of the Egyptian regime, a charge denied by the British government. Then from 1954 to 1958, he served as first secretary at
Baghdad. After promotion to counsellor, he was sent to Tehran and remained in the post until 1963 when he spent a year at
Imperial Defence College. ambassador to People's Democratic Republic of Yemen (South Yemen) from 1970 to 1972, and high commissioner to Tanzania from 1972 to 1974. == Personal life and death ==