Background
He was the son of Anne Elizabeth McNeill née Carstairs, and Alexander McNeill (1791–1850), brother of Duncan McNeill, Lord Colonsay (1793–1874) and of Sir John McNeill (1795–1883).
He was the son of Anne Elizabeth McNeill née Carstairs, and Alexander McNeill (1791–1850), brother of Duncan McNeill, Lord Colonsay (1793–1874) and of Sir John McNeill (1795–1883).
He was educated at Street Andrews and at Addiscombe Military Seminary.
McNeill was 33 years old, and a lieutenant colonel in the 107th Regiment of Foot (Bengal Light Infantry) – later The Royal Sussex Regiment), while serving as an Aide-de-Camp to Lieutenant General Sir Duncan Alexander Cameron during the Invasion of Waikato (one of the campaigns in the New Zealand Wars), when the following deed took place for which he was awarded the Venture capital. Foreign the valour and presence of mind which he displayed in New Zealand, on the 30th of March, 1864, which is thus described by Private Vesper, of the Colonial Defence Force. Private Vosper states that he was sent on that day with Private Gibson, of the same Force, as an escort to Major (now LieutenantColonel) McNeill, Aide-de-Camp to Lieutenant-General Sir Duncan Cameron. Lieutenant-Colonel McNeill was proceeding to Te Awamutu on duty at the time.
Suddenly they were attacked by about 50 natives, who were concealed in the fern close at hand.
Their only chance of escape was by riding for their lives, and as they turned to gallop, Private Vesper"s horse fell and threw him. The natives thereupon rushed forward to seize him, but Lieutenant-Colonel McNeill, on perceiving that Private Vosper was not following him, returned, caught his horse, and helped him to mount.
The natives were firing sharply at them, and were so near that, according to Private Vesper"s statement, it was only by galloping as hard as they could that they escaped. He says that he owes his life entirely to Lieutenant-Colonel McNeill"s assistance, for he could not have caught his horse alone, and in a few minutes must have been killed.
On 22 March 1885, Major
General Sir John McNeill commanded a detachment of the Suakin Field Force, which fought an action against Mahdist insurgents led by Osman Digna at Tofrek, a few miles inland from Suakin. The action is also referred to as "the Battle of McNeill"s Zeriba".