Sir Francis Harry Hinsley, OBE, FBA (26 November 1918 – 16 February 1998) was an English intelligence officer and historian.

[1] His mother Emma Hinsley (née Adey) was a school caretaker and they lived in Birchills, in the parish of St Andrew's, Walsall.

Harry was educated at Queen Mary's Grammar School, Walsall and, in 1937, won a scholarship to read history at St. John's College, Cambridge.

[3] In October 1939, while still at St. John's, he was summoned to an interview with Alastair Denniston, head of the Government Code and Cypher School (GC&CS), and was thereby recruited to Bletchley Park's naval section in Hut 4.

[5] At Bletchley Park, Hinsley studied the external characteristics of intercepted German messages, a process sometimes termed "traffic analysis": from call signs, frequencies, times of interception and so forth, he was able to deduce a great deal of information about the structure of Nazi Germany's Kriegsmarine's communication networks and even about the structure of the German navy itself.

[9] On 6 April 1946, Hinsley married Hilary Brett-Smith, a graduate from Somerville College, Oxford, who had also worked at Bletchley Park, in Hut 8.

[11] In 1962, Hinsley published Power and the Pursuit of Peace, which is important as a study of early idealist thought about international relations.