▁not ▁marry ▁until ▁he ▁was ▁aged ▁ 5 3 , ▁and ▁thus ▁died ▁in ▁ 1 7 5 8 ▁while ▁William ▁was ▁still ▁young . ▁ ▁His ▁mother ▁was ▁Har ri et ▁daughter ▁of ▁Lieutenant ▁General ▁Charles ▁Church ill . ▁ ▁William ▁was ▁probably ▁named ▁in ▁honour ▁of ▁his ▁father ' s ▁patron ▁ ▁Prince ▁William , ▁Duke ▁of ▁C umber land , ▁and ▁served ▁as ▁a ▁page ▁of ▁honour ▁at ▁the ▁Duke ' s ▁fun eral ▁in ▁ 1 7 6 5 . ▁ ▁His ▁brother ▁Ever ard ▁also ▁became ▁a ▁civil ▁servant , ▁holding ▁the ▁post ▁of ▁a ▁Commission er ▁of ▁St amps ▁from ▁ 1 7 8 3 ▁to ▁ 1 8 0 3 , ▁obtained ▁through ▁William ' s ▁influence . ▁ ▁Priv y ▁Council ▁cl erk ▁William ▁was ▁appointed ▁a ▁C ler k ▁of ▁the ▁Priv y ▁Council ▁in ▁ 1 7 7 9 . ▁He ▁held ▁this ▁post ▁until ▁at ▁least ▁ 1 7 9 5 . ▁ ▁During ▁his ▁service ▁to ▁the ▁Priv y ▁Council , ▁he ▁was ▁employed ▁on ▁various ▁diplom atic ▁miss ions . ▁ ▁In ▁ 1 7 8 3 ▁he ▁was ▁appointed ▁as ▁secretary ▁of ▁the ▁emb ass y ▁to ▁the ▁Mar qu ess ▁of ▁Car mar then , ▁who ▁was ▁appointed ▁amb assador ▁to ▁France , ▁but ▁was ▁instead ▁appointed ▁Foreign ▁Secretary ▁before ▁he ▁depart ed . ▁ ▁In ▁April ▁ 1 7 8 7 , ▁he ▁was ▁En voy ▁Ext ra ordinary ▁to ▁the ▁Grand ▁Duch y ▁of ▁T usc