I whanau a Henry Cavendish i te 10 o Oketopa 1731 i Nice, i reira tona hapu i noho ai i taua wa. Ko tana whaea ko Lady Anne de Grey, te tamahine tuawha a Henry Grey, 1st Duke of Kent, a ko tona papa ko Lord Charles Cavendish, te tuatoru o nga tama a William Cavendish, 2nd Duke o Devonshire. Ko te whanau i whai i tona whakapapa puta noa i nga rautau e waru ki nga wa o Norman, a he hononga piri ki nga whanau rangatira o Great Britain. I mate te whaea o Henry i te tau 1733, e toru marama i muri i te whanautanga o tana tama tuarua, a Frederick, a i mua tata o te ra whanau tuarua o Henry, ka wehe atu a Lord Charles Cavendish ki te whakatipu i ana tama tokorua. I whakaahuatia a Cavendish hei "The Honourable Henry Cavendish". Mai i te 11 o ona tau i haere ki te Kura Hou a Henry, he kura motuhake i te taha o Ranana. I te 18 o Noema 1748, i noho ia i Cambridge (i te 24 o Noema) i uru ia ki te Whare
1748 ngā tau