Frederic Thesiger had five male cousins by two of his father's brothers: George Handcock Thesiger (1868-1915), Gerald Thesiger (1872-1947); Arthur Thesiger (1872-1968), Bertram Sackville Thesiger (1875-1966), and Ernest Frederic Thesiger (1879-1961).

Journal references: 1

• 20 Jul 1902

See also Thesiger, Frederic John Napier