▁who ▁were ▁the ▁party ▁opposed ▁to ▁the ▁Gros ven or ▁family ▁( l ater ▁to ▁become ▁the ▁D uk es ▁of ▁West min ster ). ▁ ▁In ▁ 1 8 1 5 ▁it ▁was ▁purchased ▁by ▁Robert ▁Gros ven or , ▁who ▁was ▁at ▁that ▁time ▁Earl ▁Gros ven or ▁( and ▁who ▁later ▁became ▁the ▁ 1 st ▁Mar qu ess ▁of ▁West min ster ). ▁ ▁It ▁was ▁then ▁renamed ▁the ▁Gros ven or ▁Hotel , ▁and ▁it ▁became ▁the ▁city ' s ▁" pre mier ▁place ▁to ▁stay ". ▁While ▁it ▁was ▁in ▁possession ▁of ▁the ▁ 1 st   Mar qu ess ' ▁son , ▁Richard ▁Gros ven or , ▁ 2 nd ▁Mar qu ess ▁of ▁West min ster ▁in ▁ 1 8 6 3 , ▁this ▁building ▁was ▁demol ished . ▁ ▁The ▁building ▁now ▁present ▁on ▁the ▁site ▁was ▁originally ▁called ▁the ▁Gros ven or ▁Hotel . ▁It ▁was ▁designed ▁by ▁the ▁Ch ester ▁architect ▁Thomas ▁Main w aring ▁P enson ▁and ▁was ▁P enson ' s ▁last ▁major ▁work . ▁ ▁It ▁was ▁completed ▁after ▁his ▁death ▁by ▁his ▁elder ▁brother ' s ▁firm ▁ ▁R . ▁K . ▁P enson ▁& ▁A . ▁R itch ie . ▁The ▁hotel ▁passed ▁into ▁the ▁estate ▁of ▁the ▁Duke ▁of ▁West min ster ▁when ▁Richard ' s ▁son , ▁Hugh ▁Gros ven or , ▁was ▁advanced ▁to ▁ 1 st   D u ke ▁of ▁West min ster ▁in ▁ 1 8 7 4 . ▁On ▁