Australian Dictionary of Biography

William Kenneth Seaforth Mackenzie (1872-1952), lawyer and soldier, was born on 7 January 1872 in Sydney, son of Walter Fawkes Mackenzie, surgeon, and his wife Frances, née Usill, both English born. He was educated at Sydney Grammar School, the University of Sydney and in 1891-95 at St John's College, Oxford (B.A., 1894). He was called to the Bar at the Inner Temple, London, on 18 November 1895, and admitted to the New South Wales Bar on 2 March 1897. He practised in Sydney with Bowman & Mackenzie in 1898-1900, specializing in divorce and tenancy consultations. He was author of The Practice of Divorce in New South Wales and wrote several papers on the Landlord and Tenant Act. In 1901-14 he was in chambers at Phillip Street, Sydney.

Mackenzie's interest in soldiering extended over thirty years, commencing in 1898 when he was commissioned in the New South Wales Military Forces in the 5th Infantry Regiment (Scottish Rifles). He rose steadily through the ranks (lieutenant 1900; captain 1903; major 1907; lieutenant-colonel 1911), occupying staff and regimental appointments in the 5th Regiment and then in the 1st Battalion, New South Wales Scottish Rifles. He commanded the latter from 1909 and from 1912 the 25th (City of Sydney) Infantry.

On 26 April 1915 Mackenzie joined the Australian Imperial Force as lieutenant-colonel commanding the 19th Battalion. Embarking for Egypt in June, he landed at Anzac on 21 August and after a few weeks in which the 19th was used either in reserve or to close the dangerous gap between the Gurkhas at Susak Kuyu and the British operating from Suvla Bay, took command at Pope's Hill. For the next three months the battalion was mainly engaged in improving and extending trenches and on ration and water-carrying fatigues. His men suffered from dysentery, and Turkish broomstick bombs caused casualties. He remained at Anzac until the evacuation.

After employment in the Suez Canal defences from January 1916, on 18 March the 19th Battalion embarked for France. On 15 April it entered the front-line trenches in the Armentières sector and from 23 May was shelled daily. On 25 July the battalion entered the forward trenches covering Pozières—a 'shockingly bad relief', according to Mackenzie. 'Companies got mixed. Too many men in front-line'. Next day Mackenzie drew back one company and thinned out the line. Pozières was subjected to dreadful bombardment and casualties were severe; but for Mackenzie, they would have been worse.

Early in September the battalion moved to Ypres, Belgium, and in November entered the front line at Flers, where the trenches were in a 'dreadful state' with mud knee deep and almost waist deep in places. On 14 November, in appalling conditions, the battalion participated in an attack on The Maze. Mackenzie commanded the 19th on the Somme during the winter of 1916-17, but in February fell ill and was evacuated to England. He returned to France on 15 March but went back to England to take command of the 61st Battalion in a projected A.I.F. 6th Division. The division was never formed and in November Mackenzie was appointed to command the 2nd Australian Division Base Depot. Next month he took command of the Australian Infantry Base Depot at Le Havre. He relinquished command in June 1918 and on 23 July was attached to the 23rd Battalion. Until the Armistice he carried out legal tasks, including supervision of the conduct of field general courts martial. On 19 February 1919 he sailed for Sydney and on 6 June was demobilized.

Slightly below average height and of slim build, Mackenzie was a dignified and learned leader, well served in the 19th Battalion by a group of outstanding young officers. He felt deeply the hardships and dangers to which his men were exposed and did his utmost to alleviate them. He won the Distinguished Service Order at Pozières, 'never sparing himself during the whole time and scarcely allowed himself time for ordinary rest'. He was also awarded the (Russian) Order of St Stanislaus, 3rd class, and was thrice mentioned in dispatches.

Mackenzie resumed legal practice in 1921 in Denman Chambers, Sydney, and until 1952 was associated with leading barristers. From 1920 he was retained by the Law Book Co. as legal reporter and in 1942-51 edited the N.S.W. State Reports and Weekly Notes, establishing an unequalled record for meticulous interpretation. He was for fourteen years honorary secretary of the New South Wales United Service Institute.

Mackenzie died unmarried on 3 June 1952 at the Royal Prince Alfred Hospital, Camperdown, and was cremated. A stained-glass window to his memory is in the Sailors' and Soldiers' Memorial Church of St Luke, Clovelly.