The Saur Revolution or Sowr Revolution (Pashto: ; Dari: or , lit.'7th Saur'), also known as the April Revolution or the April Coup, was staged on 2728 April 1978 by the People's Democratic Party of Afghanistan (PDPA) and overthrew Afghan president Mohammed Daoud Khan, who had himself taken power in the 1973 Afghan coup d'tat and established an autocratic one-party system in the country. Khan and most of his family were killed at the presidential palace in Kabul by PDPA-affiliated military officers, after which his supporters were purged and killed. The revolution resulted in the creation of a socialist Afghan government that was aligned with the Soviet Union, with Nur Muhammad Taraki serving as the PDPA's General Secretary of the Revolutionary Council. Saur or Sowr is the Dari-language name for the second month of the Solar Hijri calendar, during which the uprising took place.The uprising was ordered by PDPA member Hafizullah Amin, who would become a significant figure in the revolutionary government; at a press conference in New York in June 1978, Amin claimed that the event was not a coup d'tat, but rather a popular revolution carried out by the "will of the people". The Saur Revolution involved heavy fighting in Afghanistan and resulted in the deaths of as many as 2,000 military personnel and civilians combined. It remains a significant event in Afghanistan's history as it marked the beginning of, as of 2022, 49 years of continuous conflict in the country.

Mir Akbar Khyber (Pashto: مير اکبر خيبر) (sometimes spelled Khaibar) (January 11, 1925 – April 17, 1978) was an Afghan left-wing intellectual and a leader of the Parcham faction of People's Democratic Party of Afghanistan (PDPA). His assassination by an unidentified person or people led to the overthrow of Mohammed Daoud Khan's republic, and to the advent of a socialist regime in Afghanistan, the Democratic Republic of Afghanistan.