Patterson is born on November 10, 1867 at Forgney, Ballymahon, County Longford, the son of a Protestant father and a Roman Catholic mother. He joins the British Army at Dublin in 1885 and is posted with the 3rd Dragoon Guards to India. In 1892 he is seconded to the Indian military works department as a supervisor of civil engineering projects. In 1894 he marries Frances Helena Gray, daughter of William Gray of Cork and Belfast, a building surveyor who founded the free library movement in Belfast. She goes on to earn science and law degrees.
In 1898 Patterson is sent to British East Africa to supervise 3,000 Indian and African labourers who are building a railway bridge spanning the Tsavo River as part of the Mombasa to Lake Victoria line. Construction is interrupted when two man-eating lions repeatedly attack the labourers’ camp at night. He embarks on a lion hunt, but by the time he shoots the two lions they have mauled and mutilated between 130 and 140 labourers.
Patterson volunteers for service in the South African War in 1900. He is mentioned in dispatches by Lord Frederick Roberts and Lord Herbert Kitchener and is awarded the Distinguished Service Order (DSO). In 1902 he is appointed lieutenant colonel commanding the 33rd Battalion Imperial Yeomanry. While on a shooting trip in east Africa in 1906, he discovers a new species of eland, which is named Taurotragus oryx pattersonianus after him. His account of his adventures in Africa, The Man-Eaters of Tsavo, is published in 1907 to instant international acclaim. His exploits are twice made the subject of films: Bwana Devil (1952) and The Ghost and the Darkness (1996). In 1907 he is seconded as chief game warden, British East Africa Protectorate (Kenya), and he combines his work of conducting surveys with escorting private safari parties.
The following year Patterson leads a safari trip in the protectorate accompanied by Audley James Blyth, a son of James Blyth, 1st Baron Blyth, and his wife, Ethel Jane. During the expedition Blyth shoots himself in the head with a revolver and dies. Patterson claims that Blyth was suffering from heat stroke, but there are rumours of a romantic attachment between Patterson and Mrs. Blyth. The colonial secretary Lord Crewe exonerates Patterson in return for his resignation as chief game warden. The incident serves as the plot for Ernest Hemingway‘s short story “The Short Happy Life of Francis Macomber.”
In 1913 Patterson commands the West Belfast division of the Ulster Volunteer Force (UVF), and sees service in Flanders before being sent to Egypt in early 1915. In Alexandria, two Russian Jewish Zionists, the journalist Ze’ev Jabotinsky and veteran of the Russo–Japanese War Joseph Trumpeldor, ask General John Maxwell, commander of the British forces in Egypt, to establish a Jewish legion that will liberate the Holy Land from the Turks. Maxwell refuses, proposing instead that the Jews form a volunteer transport unit to serve in Gallipoli. Patterson, who is imbued with a deep knowledge of the Old Testament, and draws spiritual sustenance from biblical heroes such as Joshua and Gideon, is appointed commander of the Assyrian Jewish refugee mule corps, a colonial corps of the Egyptian expeditionary force. He sails with the Zion Mule Corps, as it is popularly known, to Gallipoli in April 1915, where the corps serves with distinction, carrying water and ammunition to the Allied troops on the peninsula. He falls ill in November 1915, and is sent to convalesce in London. The Zion Mule Corps is evacuated from Gallipoli in December, and disbanded in March 1916.
When manpower and political considerations persuade the British authorities to create the Jewish Legion in 1917, Patterson is appointed its commander. He marches his 38th Battalion Royal Fusiliers through the City of London and Whitechapel, cheered by a crowd of several thousand Jews. The Jewish Legion participates in General Edmund Allenby‘s sustained attack, which successfully pushes the Turks out of Palestine. His experiences with his Jewish soldiers turn him into a committed Zionist. In 1916 he writes With the Zionists in Gallipoli, and in 1922 With the Judaeans in the Palestine Campaign, which contain a scathing attack on Britain’s policy towards the Jews during and after World War I.
Throughout the 1920s and 1930s, Patterson increasingly allies himself with the revisionist Zionist agenda espoused by Jabotinsky’s New Zionist Organisation. When World War II breaks out, he travels with Jabotinsky to the United States, moving permanently to La Jolla, California, in 1940. With others, including the Irish Jew and later Lord Mayor of Dublin Robert Briscoe, he agitates for the formation of a large Jewish army that would fight with the Allies against Nazi Germany. After Jabotinsky’s death in 1940, he works with Benzion Netanyahu, the Palestinian Jewish executive director of the American revisionist Zionists. In 1946 he becomes godfather to Netanyahu’s first son, who is named Yonatan (the closest Hebrew name to John) in Patterson’s honour. Yonatan later leads Operation Entebbe, the successful 1976 Israeli raid on Entebbe Airport to free Israeli hostages.
On June 18, 1947, just a year before the establishment of the Zionist state of Israel, for which he had worked so hard, Patterson dies at Bel Air, California. A week later, the United Zionist Revisionists of Great Britain hold a memorial meeting at the Anglo–Palestinian Club near Piccadilly Circus in Patterson’s memory. His documents and personal effects are held at the Jabotinsky Institute and Museum in Tel Aviv. His uniform and other memorabilia are on display in Beit Hagdudim, the Jewish Legions Museum at Netanya, Israel. His two man-eating lions are on display in Chicago’s Field Museum of Natural History, where his son Bryan Patterson later serves as curator.
(From: “Patterson, John Henry” by Yanky Fachler, Dictionary of Irish Biography, http://www.dib.ie)