Final answer:
Aksum became a trading hub due to its strategic location conducive for trade, its rich trade in valuable goods like gold, frankincense, and myrrh, and cultural developments that stemmed from its religious transformation and interactions with various empires.
Step-by-step explanation:
The reason why Aksum became a trading hub is multifaceted, largely rooted in its strategic location and the subsequent international trade networks it developed. Situated by the Red Sea with the port city of Adulis, Aksum harnessed its geographical position to facilitate trade with the Arabian Peninsula, Egypt, the eastern Mediterranean, and beyond into the Indian Ocean.
During the reign of King Ezna in the fourth century CE, the kingdom expanded its territory, which further bolstered its trade prospects. Aksum's trade included precious items such as gold, ivory, frankincense and myrrh, commodities highly valued in the ancient world. The synergy of trade, military conquests, and religious transformation, as seen in the adoption of Christianity, aided in the cultural and economic blooming of Aksum.
In addition to international commerce, Aksum's internal processes such as urban development, unique coinage, written scripts like Ge'ez, and a mix of cultural influences from Arabic, African, and Hellenic civilizations, turned it into an epicenter of wealth and power. However, environmental issues and overextension of its territory eventually led to its decline in the sixth and seventh centuries, giving way to other trading powers whilst leaving a lasting cultural legacy.