Nichols was born on 5 July 1896 in the town of Markington, Harrogate, North Yorkshire. His father was the Reverend Sebastian Elijah Nichols, an Anglican clergyman, and his mother was Caroline Isabel Mare. Nichols was educated at Eton College and, after volunteering for the British Army, shortly after the outbreak of the First World War, he was commissioned as a second lieutenant into the Lincolnshire Regiment in late September 1914. Promoted to lieutenant in early August 1915, and a captain in early June 1916, he served with the 1/5th Battalion, Lincolns, serving as part of the 138th Brigade of the 46th Division, on the Western Front for most of the war, earning the nickname of "Crasher", and being awarded the Military Cross in 1918, in addition to being twice wounded.
Between the wars
Nichols, made an honorary lieutenant in late November 1919, like many others who had joined up initially for the war, chose to remain in the army, which he did during the interwar period. He transferred to the Indian Army reserve of officers and served with the 21st Punjabis as an acting major in the Waziristan campaign, where he was awarded a Bar to his MC for operations with the Waziristan Field Force in 1921. He transferred back to the British Army to the Border Regiment in March 1922. By now a captain, and returning to England, he attended the Staff College, Camberley from 1930 to 1931, serving alongside such students as G. F. Hopkinson, M. C. Dempsey, M. A. James, J. S. Steele, W. H. E. Gott and G. W. Symes. After graduating from Camberley in December 1931 he served, from November 1932, as a General Staff Officer for Physical Training with Aldershot Command, and was promoted to brevet major in early January 1936. In February 1935 he then became a brigade major with the 13th Infantry Brigade, then commanded by BrigadierJohn Priestman and was sent to Palestine during the Arab revolt there. Relinquishing this position in February 1937, to Major Manley James, one of his fellow students at Camberley, he was promoted to permanent major in August 1937. From 1938 to 1940, he was Chief Instructor of the Senior Officers' School of the British Military Mission to the Egyptian Army, and was promoted to the local rank of lieutenant colonel.
He retired from the army as a colonel, although he had attained the rank of acting major general during his military career and most sources state he was a brigadier. He died on 7 February 1954 at Aldershot, Hampshire, at the relatively young age of 57. Nick Smart writes that the "rise and fall of 'Crasher' Nichols was due, no doubt, to a variety of factors. But what his wartime trajectory demonstrates was the importance of patronage in making or breaking an officer's career. An 'old desert hand', he had shown himself 'a brave and honourable soldier'. His 'failure' at Mareth may have been due to his own shortcomings, as Montgomery, by this time enraptured by his own 'left hook' success, expressed with such emphatic authority. But the alternative possibility, that too much was demanded of him and his Division and that blame for the failure of the frontal attack lay higher up the chain of command, has scarcely had an airing. Later in the war, Leese, Nichols' corps commander at Mareth, had to, as he put it, 'carry the can for Dickie '. The possibility remains that Leese withdrew his patronage from Nichols because, embarrassed by his own failure, he needed someone to carry his can".