Complex sentence: Muskein's force mustered 52 vessels, including a number of brigs that mounted several large cannon and were intended to provide covering fire for the landing barges, which carried between 5,000 and 6,000 French soldiers drawn largely from coastal defence units based around Boulogne.
Split into simpler sentences: Muskein's force mustered 52 vessels, including a number of brigs that mounted several large cannon and were intended to provide covering fire for the landing barges. The main body of the attacking troops numbered between 5,000 and 6,000 French soldiers drawn largely from coastal defence units based around Boulogne.