of tribes, several inscriptions and monumental buildings survive of this period which shows evidence of a wealthy, sophisticated, relatively literate society that had a rich variety of local gods and religions. Trade was already well established by the 3rd century AD, with Yemen supplying the Roman Empire with frankincense and myrrh. Further, the late 1st century AD writer Pliny the Elder mentioned that the kingdom was "the richest nations in the world". It was a hub of international trade, linking the Mediterranean, the Middle East and India. The trade linking East Africa with the Mediterranean world largely consisted of exporting ivory from Africa to be sold in the Roman Empire. Ships from Ḥimyar regularly travelled the East African coast, and the state also exerted a large amount of Influence both cultural, religious and political over the trading cities of East Africa whilst the cities of East Africa remained independent. The Periplus of the Erythraean Sea describes the trading empire of Himyar and its ruler "Charibael" (probably Karab'il Watar Yuhan'emII), who is said to have been on friendly terms with Rome: Early period During this period, the Kingdom of Ḥimyar conquered the kingdoms of Saba' and Qataban and took Raydan/Zafar for its capital instead of Ma'rib; therefore, they have been called Dhu Raydan (). In the early 2nd century AD Saba' and Qataban split from the Kingdom of Ḥimyar; yet in a few decades Qataban was conquered by Hadhramaut (conquered in its turn by Ḥimyar in the 4th century), whereas Saba' was finally conquered by Ḥimyar in the late 3rd century. Ẓafār's ruins cover scattered over 120 hectare on Mudawwar Mountain 10 km north-north-west of the town of Yarim. Early, Empire and Late/Post art periods have been identified. Around the same time in the north a Himyar General by the name of Nuh Ifriqis led an expedition to Barbaria and took control of eastern ports in modern-day Djibouti. Other Himyarite generals went as far as invading Rhapta in modern-day Mozambique. By the 4th century, the rich Himyarite export of incense, which had once supplied pagan Rome in its religious offerings, now began to wane with the Christianization of Rome, contributing to a collapse in the local economy. Jewish monarchy The Himyarite kings appear to have abandoned polytheism and converted to Judaism around the year 380, several decades after the conversion of the Ethiopian Kingdom of Aksum to Christianity (328). No changes