From Classic Encyclopedia 1911
ROHILLA (a Pushtu word for "mountaineer"), a tribe of Afghan marauders, who, towards the beginning of the 18th century, conquered a district of Hindostan, giving it the name of Rohilkhand, which still survives as an alternative title of the Bareilly division of the United Provinces. The Rohillas are chiefly notable for their association with Warren Hastings, which formed one of the main counts in his impeachment. Having been driven into the mountains by the Mahrattas, they had appealed for aid to Shuja-ud-Dowlah, wazir of Oudh, and ally of the British. The wazir promised to assist them in return for a sum of money; but when the Mahrattas were driven off the Rohilla chiefs refused to pay. The wazir then decided to annex their country, and appealed to Hastings for assistance, which was given in return for a sum of forty lakhs of rupees. Hastings justified his action on the ground that the Rohillas were a danger to the British as uncovering the flank of Oudh; and while he would never involve the company in an unjust war, neither did he desire an unprofitable one. The Rohillas were defeated by Colonel Champion in April 1774, and the majority of them fled across the Ganges; but the charges of destroying a nation, brought against Hastings by Burke and Macaulay, were greatly exaggerated. The Rohillas were never a nation, but consisted of a small body of Mahommedans, who had imposed an alien rule upon a million Hindus; and one of their chiefs was left in possession of a tract which now forms the state of Rampur.
See Charles Hamilton, History of the Rohilla Afghans (1787); and Sir J. Strachey, Hastings and the Rohilla War (Oxford, 1892).