Page 1: Biography
Thornton, Leonard Whitmore
Military leader, ambassador
This biography, written by Chris Pugsley, was first published in the Dictionary of New Zealand Biography in 2021.
Sir Leonard Thornton was New Zealand’s outstanding military leader in the second half of the twentieth century. He demonstrated leadership, administrative skill, and diplomacy in both war and peace, becoming New Zealand’s youngest brigadier at the end of the Second World War and then youngest chief of general staff as New Zealand began shifting its military focus from the Middle East to South-East Asia. Highly intelligent, articulate, and with a subtle sense of humour, Thornton possessed the gift of making anyone he spoke with feel they had his complete attention.
Leonard Whitmore Thornton was born in Christchurch on 15 October 1916, the youngest of clerk Cuthbert John Thornton and his wife Frances Caverhill Isitt’s three children. Thornton was educated at Christchurch Boys’ High School from 1930 to 1933, where he was introduced to military training as one of the school’s artillery cadets. He was prompted to pursue a military career by his uncle, Leonard Monk Isitt (later an air vice marshal).
The Royal Military College of Australia
In March 1934, at age 17, Thornton was accepted by the Royal Military College of Australia (RMC) as one of four New Zealand staff cadets on a four-year course of instruction. They were the first New Zealanders to enter the RMC since 1921 when, due to financial cutbacks, the New Zealand government withdrew all its cadets.
‘Bill’ – sometimes ‘Hank’ – Thornton was a tall, impressive figure who, with his height and reach, excelled at boxing, hockey and squash, and as a horseman. He also succeeded academically, graduating first in his class in 1937 and receiving the King’s medal for academic excellence.
The Second World War
Commissioned as a lieutenant into the Royal New Zealand Artillery (RNZA) in 1937, Thornton received further instruction in coastal artillery in Sydney before being posted to Fort Dorset in Wellington. Here he trained gunners for the coastal artillery under the newly-instituted fortress areas and fortress troops policy for protecting New Zealand’s major ports from possible attack. Thornton’s presence was immediately felt both through the standards he expected of the newly-commissioned territorial officers and in the training of regular and territorial gunners.
On the outbreak of the Second World War, Thornton was transferred to the Second New Zealand Expeditionary Force (2NZEF) and left New Zealand with the 2nd Echelon on 2 May 1940 as adjutant, 5th Field Regiment, RNZA. Deployed to Greece as battery captain 26 Battery, 4th Field Regiment, he distinguished himself in the battery action which delayed the German armoured breakout from the Vale of Tempe on 18 April 1941. His guns prevented the German forces intercepting the withdrawal of formations of the Anzac corps through the bottleneck at Larissa. In May 1941 he was posted as officer commanding, 43 Anti-Aircraft Battery of the newly raised 14th Light Anti-Aircraft Regiment, during the reorganisation and rebuilding of the 2nd New Zealand Division after its heavy losses in Greece and Crete.
In February 1942 Thornton was appointed brigade major of 6th Infantry Brigade. He returned to the gunners in September 1942 in the build-up to the Battle of El Alamein, but was immediately appointed general staff officer (grade 2) (GSO2) operations in the headquarters of 2nd New Zealand Division, sharing a tank with Bernard Freyberg as his tactical headquarters. Thornton assumed the post of general staff officer (grade 1) (GSO1) operations during the battle, owing to the illness of Colonel Queree, reverting to GSO2 operations from the advance on Tunis until the end of the North African campaign in May 1943.
Thornton found working in close proximity with Freyberg ‘a bit like sharing a bathroom with Beethoven’, but it gave him an unrivalled appreciation of Freyberg’s inclusive command style: an approach he himself adopted. In May 1943, at the age of 26, he was promoted to lieutenant colonel and posted to commanding officer, 5th Field Regiment. He deployed to Italy with the regiment and was temporarily attached to Divisional Headquarters as GSO1 operations in December 1943, on the formation of the New Zealand Corps for the Monte Cassino battles. His selection reflects Freyberg’s appreciation of his excellent staff work and his effective coordination of operations in the divisional headquarters. Thornton returned to the regiment in early April 1944 on the disbandment of the New Zealand Corps. He then served as GSO1 operations until furloughed back to New Zealand at the end of 1944. He was made a military OBE in 1944 and twice mentioned in despatches. After four months in New Zealand, he returned to Italy and succeeded Brigadier Queree as commander Royal Artillery (CRA) after the surrender, an ‘exceptional achievement for a 28-year-old: he was New Zealand’s youngest brigadier.’1 As CRA he oversaw his command’s return home and disbandment at the end of the war. Thornton was then appointed to Jayforce, the force occupying defeated Japan, serving as senior British liaison officer in the Tokyo sub-area.
On 2 May 1942 in Haifa, Palestine, Thornton had married Sergeant Gladys Janet Sloman; she was the first New Zealand VAD in 2NZEF to be married overseas. They would have three sons, two of whom followed their father into military careers.
Forming the New Zealand Army
Thornton returned to New Zealand in July 1946 as GSO1 for operations and training at army headquarters, and was appointed deputy chief of general staff in 1948. He was immersed in the planning for the reorganisation and formation of the New Zealand Army and in overseeing the preparations for the introduction of compulsory military training (CMT) in 1950. It was to be a single unified force, with all members of the regular force undergoing courses on methods of instruction and the preparation of lessons and lectures for the first CMT intake. All of this was overseen by ‘Colonel Bill’ in his capacity as commandant of Linton military camp near Palmerston North. He set the example by involving himself, as a student, in every aspect of the syllabus, to make the point that all those in the army were ‘regimental soldiers again.’2
Thornton also coordinated a questionnaire that was distributed to former 2NZEF commanders at various levels on the performance of New Zealand soldiers in battle. This was in response to S.L.A. Marshall’s publication Men against fire (1947), which argued that less than one in four United States infantrymen fired their weapons in combat. This resulted in the Thornton-edited New Zealand Army pamphlet Infantry in battle (1950), which denied that Marshall’s findings applied to New Zealand’s forces. It was a rare initiative at a time when operational and tactical training was based on British Army publications. In the 1980s, long after its existence had been forgotten in the New Zealand Army, it was still being issued to all students at the British Army Staff College in Camberley.
Shifting focus to South-East Asia
In 1952 Thornton attended the Imperial Defence College in London, where he was then posted as chairman of the New Zealand joint services staff. During this time and together with Australian military representatives, he met with the British chiefs of staff to work out details for the establishment of a British Commonwealth Far East Strategic Reserve. This signalled the increasing shift of New Zealand’s defence commitments from the Middle East to South-East Asia and highlighted Thornton’s diplomatic skills. Thornton, a skilled, firm, and personable administrator, held all the senior staff positions on the army general staff, serving as quartermaster general in 1955 and as adjutant general from 1956 to 1958. He was made a CBE in 1957.
In March 1957 the South-East Asia Treaty Organisation (SEATO) military planning office opened in Bangkok with the task of producing contingency plans against a range of scenarios. Thornton became its first chief of military planning, and involved himself in the military and political realities of campaigning in South-East Asia. Thornton and his mentor, Major-General (later Sir Stephen) Weir, dominated the New Zealand Army during these years. Weir was chief of general staff (CGS) from 1955 to 1960, and was then appointed chief military adviser to Walter Nash’s Labour government in New Zealand’s first step towards the establishment of an integrated defence headquarters. Weir, more than any other person, influenced the nature of New Zealand’s military presence in Asia.
Thornton returned to New Zealand in 1960 and, at the age of 43, succeeded Weir as CGS, making him the youngest person to hold the position in the history of the New Zealand Army. An Auckland Star editorial praised him as ‘unquestionably one of the most brilliant officers … New Zealand has produced. His record in peace and war speaks for itself.’3 He held this appointment until 1965, then succeeded Rear Admiral Sir Peter Phipps as chief of defence staff, a position he retained until 1971. The Thornton years encompassed the critical period of SEATO planning, the Thailand commitments, the Confrontation in Borneo and the Vietnam War. As committed as Weir to South-East Asia, Thornton found and juggled the resources needed to meet New Zealand’s myriad commitments throughout the 1960s. He was made a CB in 1962 and appointed a KCB in 1967.
As CGS Thornton opposed secretary of defence Jack Hunn’s plan for the formation of a totally integrated defence force on the Canadian model. Thornton wanted to retain the integrity of each of the services, and worked closely with John Robertson, the new secretary of defence, in developing ‘a strategy for change.’4 Service resistance was broken down by describing those affected by it as partners rather than as adversaries. This process was successfully brought to completion in 1971. The service boards were abolished but the services themselves retained their separate existence. Command of the armed forces was vested in the Defence Council but exercised by the chief of defence staff through the three chiefs of staff, who remained the heads of their respective services. On this basis, a diarchic system evolved where the secretary of defence took responsibility for administration and the chief of defence staff for command and control of the armed forces.
Lady Gladys died in 1969, and on 15 November 1971, in Lower Hutt, Sir Leonard married Ruth Jocelyn Leicester, a senior officer in the Ministry of Foreign Affairs. Sir Leonard had ended his military service the previous month, on reaching the retiring age for rank of 55 years. He concluded his tenure by speaking at his final press conference of his concern at the rundown in equipment and resources of the defence forces. It was a theme he would return to during his retirement, earning him the ire of Prime Minister David Lange as one of the ‘geriatric generals’ when he and former military colleagues expressed their professional judgement on the anti-nuclear and ANZUS debates.
Thornton served as New Zealand’s ambassador to South Vietnam and the Khmer Republic from 1972 to 1974, where his knowledge of the issues and the personalities allowed him to assess and advise the government during New Zealand’s withdrawal of its combat elements from South Vietnam.
Later life and legacy
Sir Leonard Thornton served as chairman of the Alcoholic Liquor Advisory Council from 1976 to 1983 and was the first lay member of the Medical Practitioners Disciplinary Committee from 1978 to 1986. He also narrated the award-winning documentary Gallipoli: the New Zealand story (1984), and scripted and narrated the television series Freyberg VC (1987). A keen fly fisherman and gardener, he also painted in watercolour and oils and loved music. Sir Leonard died in Wellington on 10 June 1999, aged 82. Lady Ruth Thornton died in 2018.
Major General Piers Reid’s assessment of Thornton’s achievements is a fitting summation of this outstanding New Zealander. ‘Not only did he achieve unparalleled success and promotion at a very early age on the battlefield but he also proved himself an extraordinarily able senior commander, administrator and diplomat in peace. … Thornton appeared to epitomise the traits of a natural leader. Yet much of his success derived from his remarkable skills as an administrator, organiser and staff officer. Thornton’s contributions to New Zealand extended well beyond the Second World War and even today his influence is felt in the structure and values of the New Zealand Defence Forces.’5 Sir John White, who served with Sir Leonard in Freyberg’s headquarters, described him as ‘a person who sought excellence and found it. Whatever he took up, he sought to do it very well. He was the sort of man who would have succeeded in any walk of life he wanted to have taken up.’6