He had two full brothers, Robert and John, and three half-siblings born of his father Ieuan ap Robert's second marriage to Gwenhwyfar ferch Madog Vaughan of Llwyn Dyrus, they being Gruffudd Vaughan, Ieuan and an unnamed sister.
He purchased and rebuilt Gwydyr Castle after it was destroyed in the 1460s and made it the family home.
[1] To avoid implication in the feuds of his kinsmen in Eifionydd, Maredudd purchased the lease of Dolwyddelan Castle about 1489.
He finally purchased Gwydyr from Dafydd ap Hywel Coetmor about 1500.
He married firstly Alice, the natural daughter of Gwilym ap Gruffudd ap Robin of Cochwillan, with whom he had four sons – John Wyn ap Maredudd, who succeeded him, Rhys Wyn, William Wyn and Rhydderch – and six daughters.