 Whish was born in London, the son of General Sir William Whish, Royal Artillery, and his wife Mary, née Hardwicke.In 1851, Whish served in India under the 14th Light Dragoons as an interpreter and bazaar master, officer of public works and assistant quartermaster general of cavalry on General Jacob's staff during the Persian campaign of 1856.Following a promotion to captain in 1857, Whish traveled to the Australian colonies of New South Wales and South Australia to buy cavalry remounts for the Indian army.