th ▁century ▁to ▁alle vi ate ▁over c row ding ▁in ▁existing ▁parish ▁bur ial ▁grounds . ▁ ▁Background ▁For ▁hundreds ▁of ▁years , ▁almost ▁all ▁London ' s ▁dead ▁were ▁buried ▁in ▁small ▁parish ▁church y ards , ▁which ▁quickly ▁became ▁danger ously ▁over c row ded . ▁Arch itect s ▁such ▁as ▁Sir ▁Christopher ▁W ren ▁and ▁Sir ▁John ▁Van b rug h ▁de pl ored ▁this ▁practice ▁and ▁wished ▁to ▁see ▁sub urban ▁c em eter ies ▁established . ▁It ▁was ▁not ▁until ▁British ▁visitors ▁to ▁Paris , ▁including ▁George ▁Frederick ▁C arden , ▁were ▁inspired ▁by ▁its ▁P ère ▁L ach a ise ▁c emetery ▁that ▁sufficient ▁time ▁and ▁money ▁were ▁devoted ▁to ▁can v ass ▁for ▁reform , ▁and ▁equival ents ▁were ▁developed ▁in ▁London : ▁first ▁at ▁K ens al ▁Green . ▁ ▁In ▁the ▁first ▁ 5 0 ▁years ▁of ▁the ▁ 1 9 th ▁century ▁the ▁population ▁of ▁London ▁more ▁than ▁double d ▁from ▁ 1 ▁million ▁to ▁ 2 . 3 ▁million . ▁Over c row ded ▁gra vey ards ▁also ▁led ▁to ▁decay ing ▁matter ▁getting ▁into ▁the ▁water ▁supply ▁and ▁causing ▁ep ide m ics . ▁There ▁were ▁inc idents ▁of ▁gra ves ▁being ▁d ug ▁on ▁un mark ed ▁plots ▁that ▁already ▁contained ▁bodies , ▁and ▁of ▁bodies ▁being ▁def iled ▁by ▁se wer ▁r ats ▁in fil tr ating ▁the ▁church y ards ' ▁dra ins ▁from ▁the ▁relatively ▁central ▁Ty burn , ▁Fle et , ▁E ff ra ▁and