Byng was deployed in November 1899 to South Africa, where he was to act as a provost marshal, but was instead immediately given the local rank of lieutenant colonel and tasked with raising and commanding the South African Light Horse during the Second Boer War.
Byng thereafter served on the front lines, during which time he ended up in command of a group of columns, was mentioned in despatches five times (including by Lord Kitchener on 23 June 1902), and in November 1900 was promoted to brevet lieutenant colonel and in February 1902 to brevet colonel.
The beginning of 1902 brought more significant events for Byng, with his return to England in March, an audience with King Edward VII the following month, at which he was appointed to the Royal Victorian Order as a member 4th class (MVO), and his marriage to Evelyn Moreton at St Paul's Church, Knightsbridge, on 30 April 1902.
Following a second visit to the King in early October, Byng was sent back to India to command the 10th Royal Hussars at Mhow and was appointed to the rank of a substantive lieutenant colonel on 11 October 1902.

In his first two years of marriage, Byng's wife suffered several miscarriages, resulting in the declaration that she would be unable to bear children.
By January 1904, Byng had also, while playing polo, broken his right elbow so severely that it was feared he would have to quit the Army.
After four months' treatment in England, though, he was pronounced to be again fit for duty and in May became the first commandant of the new cavalry school at Netheravon.
The posting was to be only a brief one, as, on 11 May 1905, Byng was made commander of the 2nd Cavalry Brigade at Canterbury, with the simultaneous temporary rank of brigadier general and substantive rank of colonel.
After appointment as a Companion of the Order of the Bath (CB) in 1906, he was again back in Aldershot, in command of the 1st Cavalry Brigade.

It was April 1909 when Byng was promoted to major-general and, though he was placed on half pay, Byng—with added income from editing the Cavalry Journal and serving as the first north Essex District Commissioner for the Boy Scouts—purchased his first house, Newton Hall, in Dunmow, Essex.
He would, however, only reside there for two years, as, exactly the same amount of time after taking command of the East Anglian Infantry Division of the Territorial Force in October 1910, Byng became General Officer Commanding the British Troops in Egypt, where he remained until the outbreak of the First World War.
He then returned briefly to the United Kingdom to take leadership of the 3rd Cavalry Division before going with the British Expeditionary Force to France and the First Battle of Ypres.
His actions there were rewarded in March 1915 with appointment as a Knight Commander of the Order of St. Michael and St. George.

After three months serving as commander of the Cavalry Corps, beginning in May 1915, at which time he was also made a temporary lieutenant-general, Byng was off to Gallipoli to head the IX Corps and supervise the successful British, Australian, and New Zealand forces withdrawal from the ill-fated campaign.
For this, he was on 1 January 1916 elevated within the Order of the Bath to the rank of Knight Commander, but was not allowed much rest, as he spent the next month commanding the Suez Canal defences before returning to the Western Front to lead the XVII Corps.
By June, he was in command of the Canadian Corps and was promoted when, for distinguished service, the King made substantive Byng's rank of lieutenant-general.
Byng's greatest glory then came when he, along with his subordinate officer, the Canadian Major-General Arthur Currie, led the Canadian victory in April 1917 at the Battle of Vimy Ridge, an historic military milestone for the Dominion that inspired nationalism at home.

In June 1917, and holding the temporary rank of general, Byng took command of Britain's largest army, the Third Army, until the cessation of hostilities and, with those troops, at the First Battle of Cambrai, conducted the first surprise attack using tanks.
Byng was deployed in November 1899 to South Africa, where he was to act as a provost marshal, but was instead immediately given the local rank of lieutenant colonel and tasked with raising and commanding the South African Light Horse during the Second Boer War. Byng thereafter served on the front lines, during which time he ended up in command of a group of columns, was mentioned in despatches five times (including by Lord Kitchener on 23 June 1902), and in November 1900 was promoted to brevet lieutenant colonel and in February 1902 to brevet colonel. The beginning of 1902 brought more significant events for Byng, with his return to England in March, an audience with King Edward VII the following month, at which he was appointed to the Royal Victorian Order as a member 4th class (MVO), and his marriage to Evelyn Moreton at St Paul's Church, Knightsbridge, on 30 April 1902. Following a second visit to the King in early October, Byng was sent back to India to command the 10th Royal Hussars at Mhow and was appointed to the rank of a substantive lieutenant colonel on 11 October 1902.
In his first two years of marriage, Byng's wife suffered several miscarriages, resulting in the declaration that she would be unable to bear children. By January 1904, Byng had also, while playing polo, broken his right elbow so severely that it was feared he would have to quit the Army. After four months' treatment in England, though, he was pronounced to be again fit for duty and in May became the first commandant of the new cavalry school at Netheravon. The posting was to be only a brief one, as, on 11 May 1905, Byng was made commander of the 2nd Cavalry Brigade at Canterbury, with the simultaneous temporary rank of brigadier general and substantive rank of colonel. After appointment as a Companion of the Order of the Bath (CB) in 1906, he was again back in Aldershot, in command of the 1st Cavalry Brigade.
It was April 1909 when Byng was promoted to major-general and, though he was placed on half pay, Byng—with added income from editing the Cavalry Journal and serving as the first north Essex District Commissioner for the Boy Scouts—purchased his first house, Newton Hall, in Dunmow, Essex. He would, however, only reside there for two years, as, exactly the same amount of time after taking command of the East Anglian Infantry Division of the Territorial Force in October 1910, Byng became General Officer Commanding the British Troops in Egypt, where he remained until the outbreak of the First World War. He then returned briefly to the United Kingdom to take leadership of the 3rd Cavalry Division before going with the British Expeditionary Force to France and the First Battle of Ypres. His actions there were rewarded in March 1915 with appointment as a Knight Commander of the Order of St. Michael and St. George.
After three months serving as commander of the Cavalry Corps, beginning in May 1915, at which time he was also made a temporary lieutenant-general, Byng was off to Gallipoli to head the IX Corps and supervise the successful British, Australian, and New Zealand forces withdrawal from the ill-fated campaign. For this, he was on 1 January 1916 elevated within the Order of the Bath to the rank of Knight Commander, but was not allowed much rest, as he spent the next month commanding the Suez Canal defences before returning to the Western Front to lead the XVII Corps. By June, he was in command of the Canadian Corps and was promoted when, for distinguished service, the King made substantive Byng's rank of lieutenant-general. Byng's greatest glory then came when he, along with his subordinate officer, the Canadian Major-General Arthur Currie, led the Canadian victory in April 1917 at the Battle of Vimy Ridge, an historic military milestone for the Dominion that inspired nationalism at home.
In June 1917, and holding the temporary rank of general, Byng took command of Britain's largest army, the Third Army, until the cessation of hostilities and, with those troops, at the First Battle of Cambrai, conducted the first surprise attack using tanks. 
Julian Byng, 1st Viscount Byng of Vimy