Marchell of Dalgarth

Marchell of Dalgarth, also called Madrun, was a Welsh holy woman, born around the year 375, the only daughter of Tewdrig, chieftain of Llanfaes near Brecon. She inherited most of his lands. Her chief court was at Garth Madrun.

The winter before her marriage was especially cold, and her father sent her to Ireland to escape the cold and bring back warm clothes of animal skins. On the way a third of her servants died on the first night and half of the rest on the second. (In some accounts they were fleeing the yellow plague, but that reached Wales only in 547, so the story should be linked with another saint of the same name.) In Ireland Marchell married Amlach ap Cormac, son of an Irish chieftain, on condition that their children be raised on her lands. Their only child, Brychan, was born at Garth Madrun around the year 400. Through Brychan, Marchell was grandmother and great-⁠grandmother of many saints. At least three other saints called Marchell were her descendants.

The source gives no feast day.