- Yemen was a divided country for hundreds of years

- North Yemen gained independence from the Ottoman Empire when it collapsed in 1918

- North Yemen was then ruled by a Zaydi Shiite Imam. Zaydi Shiism is a branch of Shiite Islam found almost exclusively in Northern Yemen.

- in 1962 the military staged a coup against the Zaydi monarchy.

- the conflict lasted several years and essentially became a proxy war between Egypt (who supported the military) and Saudi Arabia (who supported the royalists).  The war ended in 1970.   The royalists and Saudis lost.

- Meanwhile, South Yemen gained its independence from British and Saudi rule in 1967.

- South Yemen aligned itself with the Soviets (the only communist country in the Arab world).

- North and South Yemen clashed for the next several decades