This question is asked in a very broad sense as the theory of the impact of the Tsetse on Sub-Saharan Africa in the years leading up to 1000 CE and beyond is highly contentious. It does however serve well as a worldbuilding question.
The theory in question considers the impact the Tsetse has on large mammals that would have been used to pull newer, more improved, plows. Older plows, which did not churn the soil that deep, were pulled by oxen or other cattle. Cattle like these found in Sub-Saharan Africa usually had some form of defense against the Tsetse’s communicable disease. However, the new and improved plows were much larger and typically needed horse power as opposed to cattle. The horse, not native to the region, had no such defense and would often succumb to the infections given by the Tsetse. So, without a huge amount of detail, the theory suggests that since Sub-Saharan Africa, which had been on par technologically with Europe and Asia, was unable to continue its trajectory.
What does a Tsetse Event Look Like
Here is the exciting part, in my opinion anyway. Implementing a theory like this into worldbuilding can lead to some exciting ideas that can be expanded upon greatly.
While my current #WIP does not have a magic system, many, if not most, fantasy works do have some form built in and these can be used as what I refer to as a Tsetse event. While I use the term “event,” this does not necessarily mean it has to be a tangible moment in time.
Let us use The Wheel of Time for instance (small in-story background info spoilers). I know there are many options to use other than Wot, however, the One Power is very well defined and its background is very well known through Jordan’s worldbuilding.
In Randland, or whatever term you wish to use for the WoT world, through the story we see that the One Power was a catalyst both for the advancements of their pre-breaking civilization as well as the cause of the Breaking. As we learn through Rand’s ancestors, we see the precise moment that led to the Breaking. The estimated elapsed time between the Breaking and the events of book one, The Eye of the World, is just shy of 3,500 years. It is 2021, placing the Breaking roughly 1480 BCE. Hatshepsut became Pharaoh of Egypt around 1473 BCE. The mighty city of Rome would not be founded for another seven centuries.
To put this in perspective, the Breaking of the World occurred almost three centuries before the ending of the Bronze Age, which has been estimated at 1200 BCE. Today, roughly 3,500 years later, we have put men on the moon (it happened, shut up), mapped the human genome, cloned animals, and split the atom. In Randland, they are still fighting with swords, ruled by superstition and fear in many places, and have made very few strides back to the technology of the jo-car as seen in Rand’s visions. The ability of the One Power to create and simultaneously destroy the achievements of Randland’s mankind is amazing.
Have you identified your worlds Tsetse event? Did you even think of this question while worldbuilding? While this may not be absolutely necessary while creating your world, I do feel addressing it can lead to not only more detail in your work, but can lead you to ideas you otherwise may not have thought of.
If you are comfortable with it, comment with your worlds Tsetse event. I would not want you to jeopardize your #WIP by sharing that which is important to your own world. Or perhaps tweet it out using the hashtag #TsetseEvent.