Final answer:
King Ezana took over the important Red Sea trade by conquering the Kingdom of Kush.
Step-by-step explanation:
King Ezana of Aksum conquered the Kingdom of Kush, which controlled southern Egypt, and took over the important Red Sea trade. This trade route was vital for the Kingdom of Aksum as it facilitated the exchange of valuable goods such as gold, silver, iron tools, cotton cloth, ivory, and spices like frankincense and myrrh.