▁Cl im bers ▁may ▁also ▁suffer ▁alt itude ▁sick ness , ▁occasionally ▁life ▁threaten ing , ▁particularly ▁if ▁they ▁do ▁not ▁acc limat ize ▁to ▁it . ▁ ▁O wn ership ▁of ▁the ▁sum mit ▁▁ ▁The ▁border ▁between ▁Italy ▁and ▁France ▁passes ▁through ▁the ▁sum mit ▁of ▁Mont ▁Bl anc , ▁making ▁it ▁both ▁French ▁and ▁Italian . ▁ ▁Since ▁the ▁French ▁Revolution , ▁the ▁issue ▁of ▁the ▁ownership ▁of ▁the ▁sum mit ▁has ▁been ▁deb ated . ▁From ▁ 1 4 1 6 ▁to ▁ 1 7 9 2 , ▁the ▁entire ▁mountain ▁was ▁within ▁the ▁Duch y ▁of ▁Sav oy . ▁In ▁ 1 7 2 3 , ▁the ▁Duke ▁of ▁Sav oy , ▁Victor ▁Ama de us ▁II , ▁acquired ▁the ▁Kingdom ▁of ▁S ardin ia . ▁The ▁resulting ▁state ▁of ▁S ardin ia ▁was ▁to ▁become ▁pre em inent ▁in ▁the ▁Italian ▁un ification . ▁In ▁September ▁ 1 7 9 2 , ▁the ▁French ▁revolution ary ▁Army ▁of ▁the ▁Al ps ▁under ▁Anne - Pierre ▁de ▁Mont es qui ou - F é z ens ac ▁seized ▁Sav oy ▁without ▁much ▁resistance ▁and ▁created ▁a ▁department ▁of ▁the ▁Mont - Bl anc . ▁In ▁a ▁treat y ▁of ▁ 1 5 ▁May ▁ 1 7 9 6 , ▁Victor ▁Ama de us ▁III ▁of ▁S ardin ia ▁was ▁forced ▁to ▁c ede ▁Sav oy ▁and ▁Nice ▁to ▁France . ▁In ▁article ▁ 4 ▁of ▁this ▁treat y ▁it ▁says : ▁" The ▁border ▁between ▁the ▁S ardin