Saint Gwenhael was a 6th-century Breton monk and missionary who served as the second abbot of Landévennec Abbey. Following the death of the monastery's founder, Winwaloe, in 532, Gwenhael was chosen to lead the community. He eventually resigned his position to travel through the Channel Islands and Ireland, where he studied the monastic traditions of Columbanus. During his travels, he worked to restore religious fervor and established numerous monasteries across several regions.