Threes bout

Threes about is a derrogatory term.... an insult derived from what were considered disgraceful events during the Sepoy Rebellion.

The Irish regiment was one of those battalions that came into the British Line from the East India Company's Europeans (after the Sepoy Rebellion of 1857), and were made Irish regiments as they had so many Irishmen in their ranks— i.e. the Dublin Fusiliers, etc. The insult 'Delhi Rebels'refers to what was called "The White Mutiny" (of 1861). The Crown transferred the Company's Europeans to the British Army — a perfectly legal matter according to the Crown lawyers—but the men thought otherwise and demanded an alternative return home or a bounty. Feelings ran very high and a vast underground movement was going on unknown to their officers, on the part of about 10,000 men. It was so serious, coming just after the mutiny of the Bengal army, that severe measures had to be taken and one artilleryman was sentenced to death. Eventually, the ill-advised action of the Crown resulted in their releasing all the men, most of whom after a holiday at home re-enlisted to return to India.

Sir George MacMunn

There are two insults in that line: "Delhi Rebels" - which aludes, as Jill above says - the Irish "mutiny" described, directed at the Irish troops, and "Threes About". Remember that the poem is written from the point of view (and the steriotyped brogue) of an Irish soldier. The line goes "They called us (i.e. the English called the Irish) "Delhi Rebels" an' we answered (to the English cavalry regiment) "Threes About".

The latter refers to the battle of Chillianwallah, where a British cavalry brigade, having become disordered in an advance through scrub/jungle, retreated (the order "Threes About" is given to turn a unit around), allegedly masking/running over their artillery supports and with one regiment (14th Light Dragoons) actually routing...