The event that occurred last among the options provided is the beginning of European colonialism in Africa.
Here’s a brief timeline of the other events for context:
- The rise of independent sultanates on the Swahili Coast occurred from around the 10th century onward.
- The establishment of a trade network that connected the Swahili Coast with various regions began around the 1st millennium CE and intensified over the following centuries.
- The fall of the Axum Empire is generally dated to around the 7th century CE.
The beginning of European colonialism in Africa occurred much later, particularly from the late 19th century onwards, during the "Scramble for Africa."