The British position on the night of the 20th extended across the isthmus, the right resting upon the ruins of Nicopolis and the sea, the left on the lake of Abukir and the Alexandria canal. The line faced generally south-west towards the city, the reserve division under Major-General (Sir) John Moore on the right, the Guards brigade in the centre, and three other brigades on the left. In second line were two brigades and the cavalry (dismounted).
On the 21st the troops were under arms at 3am, and at 3.30 the French attacked and drove in the outposts. The French army now moved forward with great rapidity in their usual formation of columns. The brunt of the attack fell upon the command of Moore, and in particular upon the 28th (Gloucestershire Regiment). The first shock was repulsed, but a French column penetrated in the dark between two regiments of the British and a confused fight ensued in the ruins, in which the 42nd (Black Watch) captured a colour. The front and rear ranks of the 28th were simultaneously engaged, and the conduct of the regiment won for it the distinction of wearing badges both at the front and at the back of their head-dress.
Other regiments which assisted in the overthrow of the French column were the 23rd, 40th and 58th. In a second attack the enemy's cavalry inflicted severe losses on the 42nd. Sir Ralph Abercromby was here engaged in personal conflict with some French dragoons, and about this time received a mortal wound, though he remained on the field and in command to the end. The attack on the centre was repulsed by the cool and steady fire of the Guards, and the left wing maintained its position with ease, but the French cavalry for the second time came to close quarters with the reserve.
About half-past eight the combat began to wane, and the last shots were fired at ten. The real attack had been pressed home on the British right, and the History of the Queen's Royal West Surrey Regiment gives no undue praise to the regiments of the reserve in saying that "the determined attack would have been successful against almost any other troops." Technically, the details of the action show that, while not markedly better in a melee than the war-seasoned French, the British infantry had in its volleys a power which no other troops then existing possessed, and it was these volleys that decided the day even more than the individual stubbornness of the men.
The 42nd, twice charged by cavalry, had but thirteen men wounded by the sabre. Part of the French losses, which were disproportionately heavy, were caused by the gunboats which lay close inshore and cannonaded the left flank of the French columns, and by a heavy naval gun which was placed in battery near the position of the 28th. The forces engaged on this day mere approximately 14,000 British to about 20,000 French, and the losses were: