He was the second son of Duke Hoël II and Duchess Hawise of Brittany.
[2] In 1084, Hoel II left the Duchy of Brittany to his eldest son, Alan Fergant, and the County of Nantes, which was not always regarded as a part of Brittany at the time, to Matthew.
Some modern historians have suggested that Hoel left his entire patrimony to Alan IV, and that Matthew only received Nantes in fief from Alan, but this is contradicted by contemporary sources.
[2] Matthew may have been counselled as ruler by his uncle, Bishop Benedict.
In any case, he died without issue and the county of Nantes reverted to his older brother, Alan Fergant.