▁York ist ▁line ▁of ▁succession ▁as ▁both ▁Edward ▁IV ' s ▁male ▁off spring ▁and ▁declared ▁he irs ▁and ▁Richard ▁III ' s ▁nep he ws . ▁In ▁order ▁to ▁bol ster ▁his ▁own ▁claim ▁to ▁the ▁throne ▁once ▁he ▁was ▁crown ed ▁king , ▁Henry ▁VII ▁married ▁Edward ▁IV ' s ▁only ▁daughter ▁( and ▁Richard ' s ▁nie ce ) ▁Elizabeth . ▁Since ▁Tit ulus ▁Reg ius ▁( pass ed ▁by ▁Parliament ▁on ▁ 2 5 ▁June ▁ 1 4 8 3 ) ▁invalid ated ▁Elizabeth ' s ▁claim ▁to ▁acc ession ▁due ▁to ▁it ▁declaring ▁her ▁and ▁her ▁two ▁brothers ▁as ▁being ▁bast ard ▁pro gen y , ▁one ▁of ▁Henry ' s ▁first ▁acts ▁as ▁the ▁newly ▁crown ed ▁king ▁was ▁to ▁order ▁Parliament ▁to ▁repe al ▁the ▁Tit ulus ▁Reg ius ▁act ▁and ▁completely ▁er ad icate ▁its ▁existence ▁from ▁its ▁records ▁so ▁that ▁her ▁claim ▁to ▁the ▁throne ▁would ▁once ▁again ▁be ▁legit imate . ▁This ▁supp ression ▁and ▁official ▁er adic ation ▁of ▁Tit ulus ▁Reg ius ▁was ▁so ▁successfully ▁executed ▁that ▁an ▁over look ed ▁manuscript ▁copy ▁of ▁the ▁act ▁wasn ' t ▁discovered ▁for ▁another ▁hundred ▁years ▁or ▁so . ▁However , ▁in ▁er adic ating ▁any ▁trace ▁of ▁Tit ulus ▁Reg ius ▁Henry ▁also ▁caused ▁the ▁line ▁of ▁acc ession ▁to ▁the ▁throne ▁of ▁her ▁two ▁brothers ▁to ▁be ▁similarly ▁legit imate ▁again , ▁hence ▁the ▁two ▁princes ▁now ▁represented ▁a ▁greater ▁obst acle ▁and ▁threat ▁to ▁Henry ' s ▁us ur p