Whakaotihia te rerenga e whai ake nei: I whanau a Lord Charles Hay c. 1700, te tuatoru o nga tama a Charles Hay, 3rd Marquess o Tweeddale, me tana wahine a Lady Susan Hamilton, te tamahine a William Douglas, Duke o Hamilton. Ko Lord Charles te teina o John Hay, 4th Marquess o Tweeddale. I uru a Hay ki te ope taua, i whakawhiwhia ki a ia hei ensign i te 2nd Regiment of Foot Guards i te 18 o Mei 1722, me te rangatira i te 33rd Regiment of Foot i te 14 o Mei 1727. I tae mai ia ki te whakapae o Gibraltar i te tau 1727, ana i te tau 1729 i mahi ia hei rangatira mo te 9th Regiment of Dragoons. I uru ia hei kaihauturu i roto i nga ope a Prince Eugene o Savoy i nga pakanga o Rhine o te tau 1734 i te Pakanga o te Whanaketanga Polani. I kōwhiria ia hei mema o te Pāremata mō Haddingtonshire i te tau 1741 ā, i te 7 o Aperira 1743 i whakawhiwhia ki a ia te mana o tētahi kamupene i roto i te 3rd Foot Guards. I whai wāhi ia ki ngā pakanga o Ūropi o te Pakanga o te Wānanga o Ahitereiria, ā, ko ia he kaitiaki, mēnā kāore i te tūturu, o te 1st Regiment of Foot Guards i te
Ko ngā pakanga o Dettingen me Fontenoy.