Ancient Somali city-states
In antiquity, the ancestors of the Somali people were an important link in the Horn of Africa connecting the region's commerce with the rest of the ancient world. Somali sailors and merchants were the main suppliers of frankincense, myrrh and spices, items which were considered valuable luxuries by the Ancient Egyptians, Phoenicians, Mycenaeans and Babylonians. During the classical era, several ancient city-states competed with the Sabaeans, Parthians and Axumites for the wealthy Indo-Greco-Roman trade. History

Ancient Greek travelers including the likes of Strabo and Cosmas Indicopleustes made visits to the Somali peninsula between the first and fifth century CE. The Greeks referred to Somalis as the Barbaria and their land as Barbars. After the Roman conquest of the Nabataean Empire and the Roman naval presence at Aden to curb pillaging, Somali and Gulf Arab merchants by agreement barred Indian ships from trading in the free port cities of the Arabian peninsula to protect the interests of Somali and Arab merchants in the extremely lucrative ancient Red Sea–Mediterranean Sea commerce, However Indian merchants continued to trade in the port cities of the Somali peninsula, which was free from Roman interference. Ancient Indian merchants brought large quantities of cinnamon from Sri Lanka and Indonesia to Somalia and Arabia. This is said to have been the best kept secret of the Somali and Gulf Arab merchants in their trade with the Roman and Greek world. The Romans and Greeks believed the source of cinnamon to have been the Somali peninsula, but in reality, the highly valued product was brought to Somalia by way of Indian ships. Through collusive agreement by Somali and Gulf Arab traders, Indian and Chinese cinnamon was also exported for far higher prices to North Africa, the Near East and Europe, which made the cinnamon trade a very profitable revenue generator, especially for the Somali merchants through whose hands large quantities were shipped across ancient sea and land routes. They also had an understanding of the monsoons, and used them to link themselves with the port cities of the Indian Ocean and the Red Sea. They also developed an understandable way of defining the islands of the Indian Ocean in their navigational reach. They would name archipelagos or groups of islands after the most important island there, from the Somali point of view. However, Indian merchants continued to trade in the port cities of the Somali peninsula, which was free from Roman interference. The Monumentum Adulitanum  a 4th-century monumental inscription by a King of Axum perhaps named Sembrouthes recording his various victories in war, copied in the 6th century by Cosmas Indicopleustes in his Christian Topography. It describes Ezana's easternmost conquest as the "land of Aromatics", also translated "Land of Incense" or "frankincense country":
I am the first and only of the kings my predecessors to have subdued all these peoples by the grace given me by my mighty god Ares [Mahram], who also engendered me. It is through him that I have submitted to my power all the peoples neighbouring my empire, in the east to the Land of Aromatics, to the west to the land of Ethiopia [Kush] and the Sasou [?Sesea]; some I fought myself, against others I sent my armies. Aromata was one of the ports that lay in a line along the north Somali coast. Aromata was the sixth port after Zeyla (Aualites), Berbera (Malao), Heis (Moundou), Bandar Kasim (Mosullon) and Bandar Alula (Akannai). It is to be identified with Damo, a site protected on the south but exposed on the north. In ancient times Somalia was known to the Chinese as the "country of Pi-pa-lo", which had four port cities each trying to gain the supremacy over the other. It had twenty thousand troops between them, who wore cuirasses, a protective body armor. According to the Chinese The people of the land of Pi-pa-lo did not eat any grains but ate a lot of meat, the people would also pick a vein of one of their oxen, mix the blood with milk and eat it raw. They did not use any clothes, but wrapped sheep’s skin around their waists which hanged down and covered them. Trade and Governance 

An Ancient Document called the  Periplus described the Political system of the city states as desentralised and lacking a strong centralised government with each port city administered by a  chief called tyrannidas. The vast majority of the settlements were found inshore, each port city had its own unmistakable character some were unwelcoming to the Romans others welcoming and often depended on the conditions and perspectives of the locals. The port cities such as Avalites were described as very unruly , Whereas other port cities  like Malao the natives were described as peacefull. A ship called the Beden was the principal ship for traders from the different city-states. It was a fast, durable, double masted ship. The Beden was used as the main trading vessel. The boat was used mainly because of its speed 

The ports of Mosylon, Mundus, Opone, Malao, Avalites And Sarapion, were trading in items such as incenses, frankincense, myrrh and cassia. The cities would engage in a lucrative trade network connecting Somali merchants with Phoenicia, Tabae, Ptolemic Egypt, Greece, Parthian Persia, Saba, Nabataea and the Roman Empire. Somali sailors used the ancient Somali maritime 

The Somali coast formed a section of the greater incense trade alongside Southeast Asia, South Asia, and southern Arabia on the Red Sea. Incense was mainstream in the Mediterranean region, where the products would be consistently used in strict religious purposes and for other everyday uses, which has made incense a noteworthy commodity in the Indian Ocean trade. List of City States 

Botiala – In ancient times, the port city of Botiala transported goods such as aromatic woods, gum and incense to Indian, Persian and Arab merchants
Aromata– Known in ancient times as the Cape of Spices, it was an important place for the ancient cinnamon and Indian spice trade. Damo – Ancient port town in northern Somalia. It likely corresponded with the Periplus "Market of Spices". Holds many historical artifacts and structures, including ancient coins, Roman pottery, drystone buildings, cairns, mosques, walled enclosures, standing stones and platform monuments. Essina – Ancient emporium possibly located between the southern ports of Barawa and Merca, based on Ptolemy's work. Gondal – Ancient town in southern Somalia. It is considered a predecessor of the port city Kismayo. Malao – Ancient port city known for its commerce in frankincense and myrrh in exchange for cloaks, copper and gold from Arsinoe and India. Mosylon – The most important ancient port city of the Somali Peninsula, it handled a considerable amount of the Indian Ocean trade through its large ships and extensive harbor. Mundus – Ancient port engaged in the fragrant gum and cinnamon trade with the Hellenic world. Opone – In ancient times, the port city of Opone traded with merchants from Phoenicia, Egypt, Greece, Persia and the Roman Empire, and connected with traders from as far afield as Indonesia and Malaysia, exchanging spices, silks and other goods. Sarapion – Ancient port city in Somalia. It is the possible predecessor of Mogadishu. Tabae – Ancient port where sailors on their way to India could take refuge from the storms of the Indian Ocean. Nikon – ancient coastal emporium in the Horn of Africa. It was situated in the vicinity of Port Dunford in the southern Jubaland. References 

City-states
Ancient cities
Ancient Somalia