Born in Holyhead, Anglesey, on 19 June 1910, Alexander James ‘Black’ MacKenzie the son of Allan James Mackenzie (a Master Mariner) and Emma Catherine Mackenzie (née Bell) of Plas Hyfyd Terrace, Holyhead.  He joined the Royal Navy Reserve as a Probationary Sub Lieutenant on 6 November 1933 and was confirmed in that rank on 17 March 1934.

After joining the Submarine Service, he was appointed to HMS L22 as the Navigator on 8 May 1934.  Alexander was promoted to Lieutenant RNR on 16 November 1935.  On 9 Apr 37 he was transferred to the Supplementary List of the Royal Navy with the seniority of 6 November 1934 and then appointed to HMS DOLPHIN on 26 April 1937 to be the Navigator of SPEARFISH from 24 May.  In July 1937, he moved on to SEVERN as the Third Hand, before then relieving the First Lieutenant in the same boat on 15 October 1939. 

‘Black’ Mackenzie joined the Commanding Officers Qualifying Course (COQC) starting on 15 August 1940 and, on successful completion, was appointed to ‘HMS URSULA in Command’ on 13 October 1940 and served in that submarine until February 1941. He was promoted to Lieutenant Commander on 19 June 1942 and an appointment to HMS P222 as Commanding Officer followed on 15 July 1942.

Alexander Mackenzie was known as the ‘Black’ Mackenzie because of his black hair to distinguish him from his compatriot Submarine Commanding Officer – Hugh Mackenzie – who was known as the ‘Red’ Mackenzie because of the colour of his hair. 

HMS P222 was lost with all hands sometime after leaving Gibraltar for a patrol off Naples on 30 November 1942.  The submarine reported her position on 7 December but did not arrive at Algiers as expected and was reported overdue on 21 December 1942. The Italian torpedo boat FORTUNALE reported carrying out an attack on 12 December 1942 in position 40º29’N, 14º20’E – southeast of Isola di Capri and this is thought to be the most likely cause of the submarine’s loss.

He was husband to Elizabeth Rees Mackenzie and is commemorated on the Portsmouth Naval War Memorial on Panel No 61 Column No 3.