This force arrived before the town, within a day of the appearance of the fleet. Marlborough had already made good use of his time, for immediately the leading vessels had effected the passage, troops were landed in boats, and the batteries attacked in rear and carried. The rest of the fleet then entered, and, on the 23rd and 24th, the troops were landed on the south bank of the river, and commenced their march towards the city, the sailors dragging the guns. Wirtemberg immediately sent to Marlborough, to claim the command of the whole force. Marlborough replied that his commission was an independent one. He denied the authority of any of William's foreign officers in Ireland, and stated haughtily that his troops were British, and he a British officer. Wirtemberg was greatly offended that the English general should affect to look down upon the Danes, Germans, French, and other foreign ragamuffins who composed his command, and he insisted strongly upon his claims. Marlborough maintained his position, and Wirtemberg was driven, at last, to propose that they should command on alternate days, and Marlborough agreed to the proposal. The position of Cork was not a strong one, although, in the days before the use of artillery, it was considered well-nigh impregnable, being built upon the islands and marshes formed by the river Lea, and completely surrounded by two branches of the river. But upon three sides it was surrounded, at a short distance only, by high hills, which completely commanded it, and these hills were defended only by castles and forts of no great strength. The garrison was but small, for the Irish were taken by surprise by the arrival of Marlborough's expedition, and had prepared only for a siege by Wirtemberg and his foreign division. They were therefore obliged to abandon Shandon Castle, and two adjoining forts, which defended the hills on the north of the city, and Wirtemberg's Danes at once took possession of these works, and, planting their guns there, opened fire on the northern quarter of the city. Marlborough constructed his batteries at a monastery called the Red Abbey, on the south point of the river, where he was separated from the city only by the stream and narrow strip of marshy ground. These guns soon made a breach in the walls, and Marlborough prepared to storm the place, for, at low tide, it was possible to wade across the marsh and river.