Siege of Drogheda - The Siege

The Siege

Cromwell arrived at Drogheda on 3 September and his siege guns, brought up by sea, arrived two days later. His total force was about 12,000 men and eleven heavy, 48-pounder, siege artillery pieces.

Drogheda's defences consisted of medieval curtain walls. These were high but relatively thin, making them vulnerable to cannon fire. Most of the town was situated on the northern bank of the river Boyne but its two main gates, the Dublin and Duleek gates, were in an enclave south of the river.

Cromwell positioned his forces on the south side of the river Boyne in order to concentrate them for the assault, leaving the northern side of the town open and covered by a small screen of cavalry. A squadron of Parliamentarian ships also blockaded the harbour of the town.

In a letter to William Lenthall, Speaker of the English House of Commons, written shortly after the storming of the town, Cromwell explained why he did not fully invest the town—an action that would have left his divided command vulnerable to an attack by a relieving force and a simultaneous sortie by the garrison—but rather concentrated his troops on the south side of Drogheda for a swift assault.

The officers and soldiers of this Garrison were the flower of their Army. And their great expectation was, that our attempting this place would put fair to ruin us: they being confident of the resolution of their men, and the advantage of the place. If we had divided our force into two quarters to have besieged the North Town and the South Town, we could not have had such a correspondency between the two parts of our Army, but that they might have chosen to have brought their Army, and have fought with which part 'of ours' they pleased,—and at the same time have made a sally with 2,000 men upon us, and have left their walls manned; they having in the Town the number hereafter specified, but some say near 4,000. —Oliver Cromwell,