 Kọ itẹsiwaju fun paragirafi yii - Monarch ni iṣẹ ti nṣiṣe lọwọ pupọ, ti o ja ni ogun akọkọ rẹ ni 1778 ni Ogun akọkọ ti Ushant ati keji rẹ labẹ Admiral Rodney ni Cape St. Vincent ni 1780. O ja ninu ọkọ oju omi van ti Graves ni Ogun ti Chesapeake ni 1781 labẹ Admiral Francis Reynolds. Ní ìbẹrẹ ọdún 1782 ó kópa nínú ìkọlù Sint Eustatius, Ìgbésẹ ọjọ kẹrin oṣù kejì ọdún 1781, Ìjà Saint Kitts : , Ogun ti Saintes ati, Ogun ti Mona Passage. Ní ọdún 1795 ó wà nínú ọkọ ojú omi kékeré tí Admiral George Elphinstone darí tí ó gba Cape of Good Hope lọwọ Dutch East India Company ní Ogun Muizenberg. Ni 1797 Monarch ni Vice Admiral Richard Onslows flagship ni Ogun ti Camperdown, labẹ Captain Edward OBryen, ati ni 1801 o jẹ apakan ti Admiral Nelsons fleet ni Ogun ti Copenhagen, nibi ti o ti pa olori rẹ, James Robert Mosse ati pe o jiya diẹ sii ju awọn alailanfani 200 pẹlu 55 ti o ku, nọmba ti o ga julọ ti awọn alailanfani ti eyikeyi ọkọ oju-omi ti o ni ipa ninu ogun naa. 