Indeed, north yemen and South Yemen were separate countries from 1967 to 1990 and fought a civil war in 1994.
southwestern region of Arabia, from Arabic Yemen, literally "the country of the south," from yaman "right side" (i.e., south side, if one is facing east). The right side regarded as auspicious, hence Arabic yamana "he was happy," literally "he went to the right," and hence the Latin name for the region in Roman times, Arabia Felix, lit, "Happy Arabia."
Now the Republic of Yemen. Yemen is at the mouth of the Red Sea, in the southwestern corner of the Arabian Peninsula, bordered by Saudi Arabia to the north and Oman to the east; formerly divided into North Yemen (the Yemen Arab Republic) and the People's Democratic Republic of Yemen.
Note: Northern Yemen became an independent country after World War I.
Note: Southern Yemen won independence from Britain in 1967 and became the world's only communist Arab state.
Note: The two Yemens were reunified as a result of the democratic reforms of the Soviet Union and its satellite countries in 1990.