According to this account, Marcomer, Sunno and Genobaud invaded the Roman provinces Germania Inferior and Gallia Belgica in Gaul.
They broke through the limes, killed many people, destroyed the most fruitful lands and made the city of Cologne panic.
When the Roman generals Magnus Maximus, Nanninus and Quintinus heard the news in Trier, they attacked those remaining Frankish forces near the Silva Carbonaria and killed many of them.
Later, after the 388 fall of Magnus Maximus, Marcomer and Sunno held a short meeting about the recent attacks with the Frank Arbogastes, who was a general (magister militum) in the Roman army.
[citation needed] According to the later Liber Historiae Francorum, Marcomer was a descendant of the Trojans and a son of a king called Priam.