While Llewelyn undoubtedly existed, concrete details of his life are scant (it has been stated that all that is known of him is "his name, his politics and his alcohol consumption"). was recorded as holding the constableship of Caeo in 1359 for the sum of £8 per annum; Gruffydd's wife (and therefore Llewelyn's mother) was said to have been Jonnett, daughter of Gruffydd ap Llewelyn Foethus of
Dryslwyn Castle. As one of the Scudamores married Glyndŵr's daughter
Alys, this suggests significant family links between Llewelyn ap Gruffydd Fychan and Glyndŵr. Dwnn claims that Llewelyn's son Morgan became the Abbot of
Strata Florida later in his life, "and was a man held in great respect". as holding
Mallaen in the parish of Caeo, and traces the family back to Selyf, King of Dyfed through the lords of Caeo and Cilycwm. Llewelyn's (probable) grandson, Llewelyn ap Gwilym ap Llewelyn, was said by
Edward Lhuyd to have lived at the mansion of Neuadd Fawr at Cilycwm, where his "motto over his door was
Gresso pan dhelech, a chennad pan vynnech, a phan dhelech tra vynnecli trig" ==Statue==