 Gummarus and his wife eventually separated.He became a hermit at Nivesdunc and the town of Lier, Belgium grew up around the site of the hermitage where he died in 774..
Other sources place his time of death around 714.The latter is more likely the true time of death as Gummarus was said to have met saint Rumbold of Mechelen

Brouwerij Cornelissen of Limburg, Belgium brews an award-winning Sint Gummarus Tripel.