The Kingdom left an extensive architectural legacy, being one of the major medieval Somali powers engaged in sophisticated and advanced castle, fortress and various of architectures. Many of the ruined fortifications dotting the landscapes of southern Somalia today are attributed to the Ajuran Sultanate's engineers, including a number of the pillar tomb fields, necropolises and ruined cities built in that era. During the Ajuran period, many regions and people in the southern part of the Horn of Africa converted to Islam because of the theocratic nature of the government. The royal family, the House of Garen, expanded its territories and established its hegemonic rule through a skillful combination of warfare, trade linkages and alliances.
The House of Garen was the ruling hereditary dynasty of the Ajuran Sultanate. Its origin lies in the 9th century during the Mogadishu Sultanate which it succeed from during the early 13th century and began to rule southern and central Somalia and eastern Ethiopia. With the migration of Somalis from the northern half of the Horn region to the southern half, new cultural and religious orders were introduced that influenced the administrative structure of the dynasty, a system of governance which began to evolve into an Islamic government. Through their genealogical Baraka, which came from the saint Balad (who was known to have come from outside the Garen Kingdom), the Garen rulers claimed supremacy and religious legitimacy over other groups in the Horn of Africa. Balad's ancestors are said to have come from the historical northern region of Berbera.
With the centralized supervision of the Ajuran, farms in Afgooye, Bardera and other areas in the Jubba and Shabelle valleys increased their productivity. A system of irrigation ditches known locally as Kelliyo fed directly from the Shebelle and Jubba rivers into the plantations where sorghum, maize, beans, grain and cotton were grown during the gu (Spring in Somali) and xagaa (Summer in Somali) seasons of the Somali calendar. This irrigation system was supported by numerous dikes and dams. To determine the average size of a farm, a land measurement system was also invented with moos, taraab and guldeed being the terms used.
For trade, the Ajuran Sultanate minted its own Ajuran currency. It also utilized the Mogadishan currency originally minted by the Sultanate of Mogadishu, which later became incorporated into the Ajuran Empire during the early 13th century. Mogadishan coins have been found as far away as the present-day country of the United Arab Emirates in the Middle East.
The ruler of the Somali Ajuran Empire sent ambassadors to China to establish diplomatic ties, creating the first ever recorded African community in China and the most notable Somali ambassador in medieval China was Sa'id of Mogadishu who was the first African man to set foot in China. In return, Emperor Yongle, the third emperor of the Ming Dynasty (1368-1644), dispatched one of the largest fleets in history to trade with the Somali nation. The fleet, under the leadership of the famed Hui Muslim Zheng He, arrived at Mogadishu the capital of Ajuran Empire while the city was at its zenith. Along with gold, frankincense and fabrics, Zheng brought back the first ever African wildlife to China, which included hippos, giraffes and gazelles.