Meanwhile Lord Canning had telegraphed to Bombay for the European troops that were returning from the Persian expedition, and to Madras, Ceylon, Burma, and Singapore for every European soldier that could be spared. His object was to form a European column at Calcutta, and to push it up the valley of the Ganges with all speed to Allahabad, to crush any incipient mutiny on the way, and to penetrate and suppress the growing disaffection in Oudh and the North-West Provinces. It was out of the question that a column from Calcutta could reach Delhi, and he looked to Mr. John Lawrence, the chief commissioner of the Punjab on the other side of Delhi, to send all the Europeans and artillery he could spare to join General Anson. [Sidenote: General Barnard.] Sir Henry Barnard succeeded Anson as commander-in-chief. He pushed on the force to Alipore, within ten miles of Delhi. On the 7th of June he was joined by the European brigade from Meerut, and prepared to advance against Delhi. [Sidenote: Rebel position.] By this time the Delhi rebels were prepared to await an attack in the open. They had taken up a strong position to the right of the great trunk road leading to the city, and had utilised its natural advantages with remarkable skill. One body of rebels was posted in a vast caravanserai; a square enclosed by walls, with towers at the four corners. The walls were loop-holed for musketry, and the towers were occupied by sharp-shooters. In front of the caravanserai they had a battery of artillery and a howitzer, raised on an elevation and defended by earthworks, faggots and gabions. The main force, however, was posted in a neighbouring village, where the houses and gardens furnished an excellent cover for infantry. This position was defended by seven regiments of sepoy infantry, two of sepoy cavalry, and a strong battery of sepoy artillery. To those regular forces were added the artillerymen of the palace at Delhi, and volunteers of all kinds, attracted by hatred of the Feringhi, enthusiasm for Islam, and thirst for blood and plunder. [Sidenote: Battle of the Serai.] The battle of Serai was fought on the 9th of June. At sunrise Sir Henry Barnard advanced with two regiments of European infantry and two guns. He could not silence the fire of the rebel battery, and it was carried with the bayonet by a regiment of European infantry. Meanwhile the other regiment drove the rebels away out of the village. The combined British force stormed the caravanserai and gave no quarter. At this juncture Brigadier Hope Grant appeared with three squadrons of cavalry and two guns, and utterly routed the rebel army and pursued it to the suburbs of Delhi. [Sidenote: Return to the Ridge.] That same afternoon the British returned as conquerors to the old cantonment on the Ridge. Within a month of the revolt, they had avenged the massacre at Delhi, and restored the prestige of British sovereignty. [Sidenote: Sepoy vagaries.]