▁the ▁death s ▁of ▁both ▁Thomas ▁ap ▁V aug han ▁( d . ▁ 1 4 6 9 ) ▁and ▁his ▁son ▁Richard . ▁As ▁bef itted ▁a ▁manuscript ▁produced ▁for ▁wealth y ▁pat rons , ▁the ▁White ▁Book ▁was ▁a ▁substantial ▁document ▁written ▁on ▁cost ly ▁v ell um , ▁taking ▁its ▁name ▁from ▁the ▁colour ▁of ▁its ▁binding . ▁ ▁The ▁scholar ▁John ▁Dav ies ▁of ▁Mall w yd ▁trans cribed ▁a ▁number ▁of ▁po ems ▁from ▁the ▁White ▁Book ▁into ▁a ▁manuscript ▁now ▁known ▁as ▁Pen iar th ▁ 4 9 . ▁The ▁ 1 7 th - century ▁anti qu ary ▁Robert ▁V aug han , ▁who ▁referred ▁to ▁the ▁White ▁Book ▁as ▁" a ▁very ▁fair ▁and ▁ancient " ▁manuscript , ▁also ▁copied ▁parts ▁of ▁it ▁and ▁used ▁it ▁as ▁a ▁gene alog ical ▁source ; ▁V aug han ▁was ▁also ▁responsible ▁for ▁ident ifying ▁G lyn ▁C oth i ' s ▁hand ▁in ▁the ▁White ▁Book . ▁Other ▁later ▁research ers ▁made ▁copies ▁of ▁various ▁individual ▁sections , ▁such ▁as ▁Mos es ▁Williams , ▁who ▁trans cribed ▁parts ▁into ▁L lan ste phan ▁MS . ▁ 7 4 . ▁ ▁The ▁manuscript ▁came ▁into ▁the ▁possession ▁of ▁the ▁collect or ▁and ▁anti qu ary ▁William ▁Maurice ▁( d . 1 6 8 0 ), ▁and ▁was ▁subsequently ▁sold ▁along ▁with ▁the ▁rest ▁of ▁Maurice ' s ▁library ▁to ▁Sir ▁William ▁Williams . ▁The ▁library ▁was ▁ultimately ▁moved ▁to ▁the ▁m ansion ▁of ▁W yn n st ay