Yemen has long existed at the crossroads of cultures. It linked some of the oldest centres of civilization in the Near East by virtue of its location in South Arabia.
Between the 12th century BC and the 6th century AD, it was home of the Minaean, Sabaean, Hadhramaut, Qataban, Ausan, and Himyarite kingdoms, which controlled the lucrative spice trade, and later came under Byzantine and Persian rule.
In the 5th century AD, the Himyarite king Abu-Karib Assad converted to Judaism after expanding his kingdom to include most of the Arabian peninsula and parts of East Africa. Following intervention by the Byzantines and the Ethiopians, Christianity was briefly re-established in the kingdom under the leadership of Abraha. In the 7th century, Islamic caliphs began to exert control over the area. After this caliphate broke up, Yemen came under the control of many dynasties who ruled part, or often all, of South Arabia Mecca and most of Oman and even some parts of Gujarat in India during the rule of Queen Arwa al-Sulayhi.
Imams – descendants of prophet Muhammad also known as sayyids – ruled Yemen intermittently for 980 years, establishing a theocratic political structure that flourished and covered at its pinnacle all the area south of Mecca to Dhoffar in Oman and all the way to Aden and the African coast of the Red sea, Gulf of Aden and parts of the Indian ocean adjacent to the Arabian Peninsula and strongly influencing and sometimes controlling sharifs of Hejaz. It survived until modern times.
Egyptian Shia caliphs occupied much of Yemen throughout the 11th century but were resisted by the Imams. By the 16th century and again in the 19th century, Yemen was part of the Ottoman Empire (first as the Eyalet of Yemen, later as the Vilayet of Yemen), and in some periods Imams exerted control over all Yemen.
Aden was occupied by the Portuguese between 1513 and 1538, and again from 1547 to 1548. In between those Portuguese occupations, Aden was
