, ▁Cast leton ' s ▁early ▁history ▁is ▁marked ▁by ▁its ▁status ▁as ▁a ▁town ship ▁within ▁the ▁ancient ▁parish ▁of ▁Ro ch dale . ▁Prior ▁to ▁mer ging ▁with ▁the ▁County ▁Bor ough ▁of ▁Ro ch dale ▁in ▁ 1 9 0 0 , ▁Cast leton ▁experienced ▁rapid ▁growth ▁during ▁the ▁ 1 9 th ▁century ▁as ▁a ▁mill ▁town ▁in ▁its ▁own ▁right , ▁facil itated ▁for ▁the ▁most ▁part ▁by ▁the ▁construction ▁of ▁the ▁Ro ch dale ▁Canal ▁which ▁is ▁rout ed ▁through ▁the ▁area . ▁Cast leton ' s ▁growth ▁was ▁significant ; ▁so ▁much ▁so , ▁that ▁for ▁a ▁time ▁it ▁was ▁almost ▁the ▁same ▁size ▁of ▁nearby ▁Ro ch dale . ▁ ▁Loc ated ▁between ▁j unction s ▁ 1 9 ▁and ▁ 2 0 ▁of ▁the ▁M 6 2 ▁motor way , ▁Cast leton ▁today ▁is ▁a ▁pre domin antly ▁resident ial ▁area , ▁with ▁a ▁total ▁population ▁of ▁ 9 , 7 1 5 , ▁increasing ▁to ▁ 1 0 , 1 5 9 ▁at ▁the ▁ 2 0 1 1 ▁Census . ▁ ▁History ▁ ▁The ▁most ▁ancient ▁known ▁reference ▁to ▁Cast leton ▁is ▁found ▁in ▁the ▁Dom es day ▁Book ▁( 1 0 8 6 ). ▁The ▁name ▁suggests ▁a ▁link ▁with ▁a ▁fort ification ; ▁the ▁Cast leton ▁area ▁was ▁the ▁site ▁of ▁Ro ch dale ▁Castle . ▁The ▁castle ▁is ▁believed ▁to ▁have ▁been ▁located ▁on ▁the ▁south ▁bank ▁of ▁the ▁River ▁Ro ch , ▁which ▁runs ▁through ▁Cast leton .