Still, the breach was day by day becoming more practicable, and Tippoo, alarmed at the progress that had been made, moved his army down towards the east side of the fort, and seemed to meditate an attack upon our batteries.

He placed some heavy guns behind a bank surrounding a large tank, and opened some embrasures through which their fire would have taken our trenches, which were now pushed up close to the fort, in flank.
Lord Cornwallis at once directed a strong force to advance, as if with the intention of attacking the new work, and Tippoo ordered his troops to retire from it.

It was evident, however, that he had determined to give battle in order to save the fort, and the English general therefore determined to storm the place that very night, the 21st of March.

The preparations were made secretly, lest the news should be taken to Tippoo by one of the natives in the town, and it was not until late in the evening that orders were issued to the troops which were to take part in the assault.
The column was to be composed of the grenadier and light companies of all the European regiments, and these were to be followed and supported by several battalions of Sepoys.

The force, commanded by Colonel Maxwell, at eleven o'clock issued from the town and advanced through the trenches.