Following Khmer Rouge border attacks, Vietnam invades Cambodia, takes Phnom Penh on 7 January 1979 and overthrows the Khmer Rouge; Vietnamese troops remain until 1989.
Vietnam becomes the 149th member state of the United Nations.
China attacks Vietnam's northern border provinces and withdraws after about a month; both sides claim victory.
The National Assembly of the reunified country proclaims the Socialist Republic of Vietnam; Saigon is renamed Hồ Chí Minh City.
Hundreds of thousands of people flee Vietnam by sea after 1975; many die at sea and others are resettled, mostly in Western countries.
Beginning with the attack on Buôn Ma Thuột, North Vietnamese forces advance across the South, leading to South Vietnam's collapse on 30 April 1975.
The Khmer Rouge capture Phnom Penh and forcibly empty the cities; Pol Pot's regime causes the deaths of an estimated 1.5 to 2 million people.