Well, sister Somalis have some of the richest history and advanced civilizations across Africa and I'll list them for you but there are many so I will only mention the famous ones.
Land of Punt, also known as the Punt Kingdom located in modern day of northern Somalia where it's Somalis ancestral homeland and where Somalis are proven to be the direct decedents of ancient Puntites.
Punt Kingdom was famous for trading and sending embassies to many ancient Kingdoms around the world and were a regional power. They sent arm forces to protect Egyptian Empire and successfully crushed the Hittites and the Puntites had a similar culture and architecture of Egypt meaning Egyptian Empire could've possibly been Cushitic.
Macrobia Kingdom
In the classical era, the Macrobians, who were direct ancestors of Somalis, established a powerful tribal kingdom that ruled large parts of modern Somalia. They were reputed for their longevity and wealth, and were said to be the "tallest and handsomest of all men".[26] The Macrobians were warrior herders and seafarers. According to Herodotus' account, the Persian Emperor Cambyses II, upon his conquest of Egypt (525 BC), sent ambassadors to Macrobia, bringing luxury gifts for the Macrobian king to entice his submission. The Macrobian ruler, who was elected based on his stature and beauty, replied instead with a challenge for his Persian counterpart in the form of an unstrung bow: if the Persians could manage to draw it, they would have the right to invade his country; but until then, they should thank the gods that the Macrobians never decided to invade their empire.[26][27] The Macrobians were a regional power that were known from east to west and were highly advanced in architecture and extremely known for their wealth were they were noted for its gold, which was so plentiful that the Macrobians shackled their prisoners in golden chains.[27]
Queen Arawelo: A powerful Queen ruler of Macrobia.
Somali city-states
The Somali city states had number of well build city-states but were ancient tribal Somali kingdoms which is why they are referred as the Somali city states instead.
During the antiquity times, the Somali city-states that in engaged in a lucrative trade network connecting Somali merchants with Phoenicia, Ptolemic Egypt, Greece, Parthian Persia, Saba, Nabataea and the Roman Empire. Somali sailors used the ancient Somali maritime vessel known as the beden to transport their cargo.
Here is what the ancient Chinese said about the Somali city-states.
In ancient times Somalia was known to the Chinese as the "country of Pi-pa-lo", which had four departmental cities each trying to gain the supremacy over the other. It had twenty thousand troops between them, who wore cuirasses, a protective body armor.[9]
The ancient Somali city-states had boats called Beden which was one of the most advanced boats in the world. Somalis were always highly sophisticated people. Here:
https://en.wikipedia.org/wiki/Beden
Now we're moving into the medieval period. Here is what Al-Yaqubi said about us.
The first clear written reference of the sobriquet Somali, however, dates back to the 9th century by Al-Yaqubi who wrote that Muslims were living along the northern and southern Somali seaboard and he referred the inhabitants as "Somaal".[38] He also mentioned that the Adal kingdom had its capital called Zeila and Mogadishu Sultanate with its capital being Mogadishu.[38][39]
Adal kingdom
Now not much is known about this Kingdom but according to Al-Yaqubi it was small but wealthy and religious. It was basically just as advance as other Kingdoms those times. It stretch from 9th century to the 13th century. Now not to be confused with the Adal Sultanate so I called this one instead early Adal Kingdom lol.
Mogadigushi Sultanate (9th century till the 13th century)
Now Mogadishu Sultanate was even more interesting.
For many years Mogadishu functioned as the pre-eminent city in the بلد البربر (Bilad al Barbar - "Land of the Berbers"), as medieval Arabic-speakers named the Somali coast.[7][8][9][10] Following his visit to the city, the 12th-century Syrian historian Yaqut al-Hamawi (a former slave of Greek origin) wrote a global history of many places he visited Mogadishu and called it the richest and most powerful city in the region and was an Islamic center across the Indian Ocean.[11][12]
It was a small Kingdom but very wealthy and powerful. Mogadishu city was already a prosperous city in the 9th century and started to get more amazing ever since. Mogadishu Sultanate had their own coins as you can see from below.
I'll get into more Somali medieval history later since it's too long and possibly early modern period. But for now I gotta go to university. Cya!