That summer, "Monmouth" took part in the Helder expedition, a joint Anglo-Russian invasion of Holland under the command of Vice-Admiral Andrew Mitchell. At the Neiuw Diep the British captured seven warships and 13 Indiamen and transports. Then Mitchell obtained the surrender of a squadron of the navy of the Batavian Republic in the Vlieter Incident. The Dutch surrendered twelve vessels ranging down in size from the 74-gun "Washington" to the 16-gun brig "Galathea". Next, "Monmouth" was among the vessels sharing in the capture on 17 August of "Adelarde". On 15 September "Monmouth", several other British vessels and two Russian, arrived at Sheerness as escort to five Dutch ships of the line, three frigates and one sloop.