You're not going to do this realistically. Stephen Barnes (I think it was) has a very good series about this (not that I can find hide nor hair of it anywhere on the internet!!!), and even that heavily invoked the MST3K Mantra for the backstory.
I dont post much on AH i rather read the many excellent TLs on here but it always distrubs me when i see what ifs about Africa developing powerful empires on par with European and Asian and this idea is usually dismissed by arguments based on two points. 1. The climate of Africa doesn't lend to supporting large modern states or 2. the level of technology doesn't lend to this.
People tend to forget Africa has supported many empires that during their particular time were 1st tier powers.
The various sultanates in Egypt, Fatimids, Mamluks
The Almoravids and Almohads of North Africa
The Ghanaian, Malian and Songhay Empires
There have also been several states who had a chance to modernize successfully, Asante, Benin, Yoruba, Ethiopia
The massive power disparity between african and european states becomes visible at the industrial revolution, you have to get an African state to pull off a meiji type modernization or have one maintain close enough contact with Europe to advance at a similar pace. To the idea of having Africa swap places with Europe and Asia well so many changes have to be made to history i dont know where to even start.
None of the extant states could "pull a Meiji", but it should be possible for a fictional state in Africa to do it. I mean, the continent is protected by a disease environment that keeps it safe from the worst of Europe's excesses, has ironworking and domesticated animals...
The "Eurasia has greater east-west extent for trade" argument doesn't make too much sense to me, except when referring to Southern Africa which is isolated in southern temperate zone. In the tropics, from Senegal to Somalia is an appreciable east-west extent in itself, and there is further potential for trade with Arabia and India, which have somewhat similar climates. The Sahel is a good east-west axis of trade.
How about having some sort of Mongol-analogue conquering across the Sahel (would horses be introduced to this region/be useful? Aren't they already in Arabia?) conquering a decent swath of West Africa and East Africa? This would make much of Africa more interconnected and more able to compete with the larger world.
The Mongols were able to travel from China to freaking Venice (though obviously they didn't quite conquer that far); that is a
lot more territory than exists in central Africa. Barring an act of God, Eurasia is always going to dominate the world for the simple reason that it already consists of most of it, has a large number of domesticables, and has two separate cradles of civilization to pull from. Most of Europe's technology at the dawn of the modern era wasn't developed in Europe but in China, India, Arabia, etc.
*Carthaginian or Egyptian voyage of exploration is lost deep into Southern Africa along with domestic animals and seeds for possible colony
Let me stop you there: No. A voyage of colonization first requires that you find somewhere worth colonizing.
*Lost ship manages to just come ashore in OTL South Africa near Capetown
Cliché Alert! Cliché alert!
*Wheat manages to disseminate into Africa slowly from the south and move north
Where it quickly dies because its not adapted to a jungle environment.
*Iron and/or copper deposits are discovered and used by colonists who marry into the local population, form the basis of an Empire
Which stagnates because it is trapped in South Africa with nowhere to expand to and no one to trade with.
The first thing to do is select a region that makes sense. Instead of sayin gAfrica, let's look at the Great Lakes Region/East Africa/Horn of Africa.
Here you have proven trade ties (think King Soloman and Queen of Sheba). Second you have outstanding agricultural land to support a large population (Ethiopian Empire throughout the ages) and proximity (as far down as Madagascar Indian Ocean traders formed a network later taken up by Yemeni Merchants.
So, assuming some geopolitical entity ranging from Ethiopia down to Tanzania with inroads encompassing the Great LAkes, you have your people. Let's assume that (a) a bit more trade was engaged in by this empire due to their stability and complexity and ability to project outward rather than warring internally, and the idea that (b) after empirical consolidation - say by the first few centuries of the modern era - a surplus of military needed to be vented off (like Spain after the inquisition needed something to do with all those men under arms) and they sent some military personnel along with trading voyages ... first to Arabia, then to South Asia, and eventually to E. Asia.
In time these voyages would spark the imagination, especially if this Rift Valley Empire was able to conquer some significant territory - ala Goa in OTL perhaps? Combine this with trade with China and the faster spread of gun powder and you (a) overcome the very real north/south versus east/west obstacles to the trade of ideas, and (b) provide Africa with the ability to arive at Europe's doorstep sometime in the second millenium and march on Europe.
Just some thoughts. But that is how I see it happening. I cannot easily imagine it coming from West Africa due to remoteness.
Huh. That actually sounds practicable.
No malaria would go a long way. Also no tse tse fly
No, no, the African disease envelope was pretty much the only thing keeping it from getting screwed over even
worse IOTL, and will be an asset when it comes to colonizing.
What could have happened if the rivalry between Rome and Carthage had gone in favor of Carthage instead of Rome? If the Carthage had won the battles and an Empire of Carthage had formed around the Mediterranean in place of the Roman Empire? If Carthage remains the capital, it will be an African Empire though not 'Black dominated'.
Doesn't count. Carthage is a Mediterranean power, not an African one.
.