As an Eton College student he assisted in thwarting Roderick Maclean's assassination attempt on Queen Victoria in 1882, before joining the Royal Horse Guards in 1887.

Wilson was promoted quickly, and as a captain was appointed aide-de-camp to Robert Baden-Powell at the start of the Second Boer War, in which role he served through the Siege of Mafeking.

During the inter-war years Wilson joined his friend Winston Churchill on a fact-finding trip to East Africa, and then participated in a controversial treasure hunting expedition in Jerusalem.

[13] Wilson then joined the regular British Army as a second lieutenant on 4 May 1887, replacing a dead subaltern in the Royal Horse Guards (Blues).

[2][1][17][18] Wilson continued in the army after his marriage; despite his relatively lowly position, the historian Brian Roberts writes that the couple "lived like plutocrats".

[20][21] After the wedding of Prince George, Duke of York, and Princess Mary of Teck on 6 July 1893, Wilson commanded the Travelling Escort that took the couple to their honeymoon at Sandringham House.

[23][1] Roberts describes Wilson in this period, saying: Gordon...was an undistinguished, homely-looking man with a large, untidy walrus moustache which, despite his laughing eyes, gave him a somewhat gloomy look.

[25][26] Also on their ship was Alfred Beit, a gold magnate and friend of the family who was a key part of the conspiracy behind the Jameson Raid, an attempt to trigger an uprising in the South African Republic.

[27][26] Upon their arrival Beit took the Wilsons to visit Cecil Rhodes at Groote Schuur, where they stayed for several days and were onlookers to discussions relating to the issues in the Transvaal.

[29] Determined to still reach the Transvaal, they then received permission to go as passengers onboard the troopship Victoria that was sailing to Durban to return Leander Starr Jameson and his raiders to Britain.

During this time the Bloemfontein Conference failed to lessen tensions between the Boer republics and Britain, and the country began to move to a war footing.

[35] Rhodes was dismissive of the situation, saying that the Boers "will bluff up to the cannon's mouth", an opinion that Wilson disagreed with, instead believing that they needed to "prepare for the worst".

[36] On 25 July Colonel Robert Baden-Powell arrived at Cape Town to raise two regiments of mounted infantry[Note 2] for the defence of Rhodesia and Bechuanaland and to protect lines of communication.

Unable to locate a recruiting post at Mafeking, in Bechuanaland, because of negative associations with the Jameson Raid,[Note 4] Baden-Powell instead situated one at Ramatlhabama just to the north.

[2] The Siege of Mafeking began on 13 October; Wilson wrote a letter to Sarah, who had left the town beforehand, describing how ineffectual the initial Boer bombardment was.

Baden-Powell initially refused to agree to the exchange, and Wilson began offering a reward to anyone in Mafeking who would take the place of his wife.

[57] After a Christmas Day truce, in the early morning of 26 December Wilson and most of Baden-Powell's staff participated in a sortie attacking Game Tree Hill, a well-placed and dangerous Boer gun emplacement.

When she also fell ill with tonsillitis they were moved to the Mafeking convent, the replacement for the destroyed convalescent home, with Wilson having to be driven there as he was unable to walk.

[62][65][66][64] On 26 January 1900 the Wilsons were dining with Major Hamilton Goold-Adams when a Boer artillery shell burst above their building, collapsing one wall on top of them.

They returned in the evening having failed to find the Boers in the worsening light, but in the night Mahon's column entered Mafeking, ending the 217-day siege.

[2][75] Wild celebrations took place in Britain after the relief, with a large crowd forming outside the Grosvenor Square house where the Wilson children were staying.

[92] Churchill wrote to Edward VII during the journey that Wilson was: an excellent traveller never not of spirits or tired or bored or vexed whatever may hap[pen].

[92][93] In 1910 Wilson spent some time in Jerusalem, and in early 1911 he became involved in his younger brother Clarence's work as part of the Parker Expedition, an attempt to find treasure in excavations of Solomon's Temple.

The following day they were attacked by a greater German force, taking heavy casualties because, cavalry not being provided with entrenching tools, their trenches were too shallow.

A borrowed rifle in his hand, a cheery laugh bubbling up, Gordon Wilson was a few feet ahead of his men when a bullet pierced his brain.

[2][107] A memorial service was held for him at Christ Church, Mayfair, and Sarah received messages of condolence from George V, Mary of Teck, Alfonso XIII, and Victoria Eugenie of Battenberg among others.

[2] His brother Herbert, who would himself be killed in 1917, sent Wilson's personal belongings home to Sarah, including a newspaper cutting of lines inspired by the play The Two Noble Kinsmen.