▁was ▁the ▁son ▁of ▁Sir ▁John ▁Sed ley , ▁ 2 nd ▁Baron et , ▁of ▁A yles ford ▁in ▁Kent , ▁and ▁his ▁wife ▁Elizabeth , ▁daughter ▁of ▁Sir ▁Henry ▁Sav ile . ▁The ▁Sed le ys ▁( also ▁sometimes ▁sp elled ▁Sid ley ) ▁had ▁been ▁prominent ▁in ▁Kent ▁since ▁at ▁least ▁ 1 3 3 7 . ▁Sed ley ' s ▁grand father , ▁William ▁Sed ley , ▁was ▁kn ight ed ▁in ▁ 1 6 0 5 ▁and ▁created ▁a ▁baron et ▁in ▁ 1 6 1 1 . ▁He ▁was ▁the ▁founder ▁of ▁the ▁Sid le ian ▁L ect ures ▁of ▁Natural ▁Philosoph y ▁at ▁Oxford . ▁Sed ley ▁was ▁educated ▁at ▁W ad ham ▁College , ▁Oxford , ▁but ▁left ▁without ▁taking ▁a ▁degree . ▁There ▁his ▁t utor ▁was ▁the ▁poet ▁Walter ▁Pope . ▁The ▁second ▁surv iving ▁son ▁of ▁Sir ▁John ▁Sed ley ▁and ▁Elizabeth , ▁William , ▁succeeded ▁to ▁the ▁baron et cy ▁in ▁ 1 6 4 5 . ▁Charles ▁Sed ley ▁inherited ▁the ▁title ▁( 5 th ▁baron et ) ▁in ▁ 1 6 5 6 ▁when ▁his ▁brother ▁William ▁died . ▁By ▁his ▁first ▁wife ▁Lady ▁K atherine ▁Sav age , ▁daughter ▁of ▁John , ▁ 2 nd ▁Earl ▁R ivers ▁he ▁had ▁only ▁one ▁legit imate ▁child , ▁Catherine , ▁Count ess ▁of ▁Dor chester , ▁mist ress ▁of ▁James ▁II . ▁The ▁couple ▁lived ▁in ▁Great ▁Queen ▁Street . ▁After ▁his ▁first ▁wife ▁had ▁been ▁sent ▁to ▁a ▁convent