English: Plan and key. The Attack on Boulogne Oct 1804 Watercolour showing the situation prior to the British assault on the night of 2 October 1804. In the foreground is the main British squadron with Admiral Lord Keith's flagship, the two-decker 'Monarch', 74 guns, in the centre and frigates and sloops around it. Behind them is a line of smaller British sloops and brigs. Behind that, to the left, a Dutch merchant ship is about to be intercepted. Some of the French invasion craft are in a line close to the shore, behind an invisible sandbank. The town and harbour of Boulogne are behind, also filled with invasion craft and with strong shoreline fortifications. Napoleon's 'Army of England' are shown encamped in the heights above the town.