why didn't Arabs or Iranians colonize East Africa in 17th-18th centuries in massive numbers?

sort of along the lines of American “Manifest Destiny”. I know that there were slave trading colonies along the coast, but why wasn’t there big population migration to there, pushing out the military and politically weaker locals? Was the population density low enough in the Middle East that they didn’t want land like Europeans wanted land in America? Or what was stopping them?

Well, a millennium earlier Arabs did spread into Egypt and the Sudan/Somalia coast, which seems fairly expansive. Moreover, they were going everywhere else at the same time: east and south to Central and South and Southeast Asia, west to North and West Africa and southern Europe, north to Anatolia and eastern Europe. If they wanted “elbow room”, there were other places to find it besides the East African interior.

And in the 17th/18th centuries there was the Ottoman Empire. Why would they be interested in massive colonization of East Africa?

The thing that made european colonization of remote locations practical, was (a) relative difference in population and (b) weaponry.

The Europeans were lucky in North America and many other points in finding a relatively nomadic population that said “if you want to put up a fort over there in return for a few beads, it’s no skin off our butt; there’s miles and miles of hunting land”. The Spanish were clever(?) in establishing themselves on easily defensible islands before taking on much of the mainland. Agricultural societies are denser and more inclined to not cede an inch of ground.

When it comes to a fight, the shock and awe of taking out a few of the natives with noisy firearms from beyond arrow range is useful. When it’s arrows against arrows, and the natives realize that taking out the horse from under you is a productive strategy, your battle options are that much more challenging. You also need the logistics to supply those invading forces, and a settled agricultural land has less hunting opportuities than a densely populated agricultural area.

If you’re lucky, you may wind up like Pizarro with an empire just getting over a civil war that has never seen a horseman before; worst case, however, is that you unite the locals against you. Even some of the earlier settlements in N. America, the locals managed to take out the invaders as often as not.

So how rich was east Africa to entice the Arabs? Good agricultural land? Other resources?

Iran in the 17th and 18th century was overwhelmingly preoccupied with its Ottoman and at times Central Asian, Mughal and much later Russian borders, where it spent much of its time on the defensive ( the late reign of Shah Abbas in the early 17th century and that of the early 18th century military phenomenon Nadir Shah excepted ). It was a land-based empire with few significant ports. The only naval adventurism was early in the 17th century, a largely defensive affair to expel the Portuguese from Hormuz.

The Indian Ocean, while not insignificant from an economic standpoint ( Ottoman copper was in high demand in India ), was very much a tertiary or even quaternary concern for the Ottomans. Their huge, sprawling state had myriad other issues to concern it on multiple fronts. It was far more of a naval power than Persia, but its activities in the Indian Ocean are mostly confined to the 16th century and expeditions against Portuguese bases in India. East Africa was way down on the list and of course by the 18th century the Ottoman state was in decline and on the defensive.

The Portuguese had pre-emptively occupied, as well as the mouth of the Persian Gulf, much of the East African coast back in the 15th-16th centuries ( it held Zanzibar by 1505 ), at least in a loose fashion. But as it happened an independent Arab power DID rise to challenge them - Oman, who had expelled ( with Persian as above and a little English help ) Portuguese occupiers of their region in the early to mid-17th century. The Ibadi Imams ( later sultans ) from Oman pursued an aggressive campaign and taking the struggle with Portugal overseas, pushed the Portuguese out of East Africa north of Mozambique ( a relative backwater ) in the late 17th century. The key event was the fall of the main Portuguese stronghold of Fort Jesus in Mombasa in 1695. They took Zanzibar island, their future capital, in 1698.

So an Arab state did come to dominate much of the East African coast. But Oman is tiny and was never very populous. There was little population pressure and few immigrants, relatively speaking, to settle the region… So it was a case of exploitation-style colonialism, rather than settlement-style colonialism. The sultanates of Oman ( the Arabian territories ) and Zanzibar ( the East African territories ) were split in the mid-19th century by inheritance. Zanzibar eventually was forced to cede its mainland possessions to far more powerful European powers like Britain, Germany and Italy in late 19th century and was eventually transformed into a dependent protectorate of Britain by 1896.

I’m sure you know this already, Tamerlane, but for the benefit of other readers I figured I’d mention that Zanzibar fell to Britain in the 38-minute Anglo-Zanzibar War, widely cited as the shortest war in history.

The success of the British colonisation effort hinged on the fact that disease had decimated the population. It had nothing to do with the native’s lack of agriculture. The natives were highly accomplished agriculture. Indeed, it was the native’s agricultural nous that saved the British from starvation, as anyone from the US who paid attention in school around the end of Novermber should know.

The parts of North America initially colonised by the British were largely occupied by sedentary agricultural people in well established villages and towns. In fact I can’t think of any regions where the population could be described as “relatively nomadic”. Certainly several groups had winter and summer villages that they moved between, but that doesn’t qualify as “relatively nomadic”.

According to The Discoverers by Daniel J. Boorstin, one big disincentive for Arab exploration any further south than Madagascar was strong winds and currents that made a return trip problematical, at least for the sailing technology of the time.

points on internal problems and lack of interest by major mideastern states well taken.

As far as claims about ability of the natives to effectively resist, I don’t buy that. Even with the same level of technology the better organized and intelligently led force force will gradually chew up numerically superior but incompetently led opposition. Just look at the British and French expansion in late Mughal India in 18th century. They were opposed by not just random tribes but by powerful states that had pretty much the same type of weaponry and a lot more manpower. Yet in the long run the locals lost and Europeans won.

Meanwhile, in 18th century population density in East Africa was a lot less than in India and there were no powerful local states. Whereas the middle eastern nations were in military capability generally comparable to contemporary Europeans.

Up until the 18th century, yes. After that there was a slow, incomplete, but nevertheless steady slide in relative capabilities, less in technology than in tactical battlefield doctrine which began to evolve rapidly in Europe from the mid-18th century on. Similarly in economic capacity and output, which informed the ability of states to project force. But to illustrate Omani effectiveness during the period they were expanding:

…The men-of-war belonging to the sultan of Muscat had a formidable reputation in the Arabian Sea. In 1695 an Omani fleet of sixteen sail was sighted in Indian waters. The Muscat Arabs had begun to fit out large warships during these years, no doubt to provide an effective force against European privateers who descended on the Arabian Sea from the West Indies in the 1690’s. The French ship Legier, of forty guns, ran into two Muscateers, of sixty and eighty guns respectively, off Goa and was promptly engaged. The action and cannonade continued until nightfall and under cover of darkness the Legier managed to get away. She arrived in Goa in shattered condition; her captain had been killed…From the available evidence one must conclude that if the balance of sea-power was unevenly distributed between the Asian merchants and the Europeans, it was perhaps more the result of different economic, social and political considerations than the technology of shipping. For when Asian seamen turned predators and had a tangible motive for gaining the day, even a heavily gunned East-Indiaman such as the Derby ( 1735 ) proved a victim.

From Trade and Civilization in the Indian Ocean: An Economic History from the Rise of Islam to 1750 by K. N. Chaudhuri ( 1985, 1993 Cambrdge University Press ).

The Spanish colonized the West Indies first mainly because that’s where they hit land first. Every area the Spanish initially colonized, including the West Indies, was occupied by agricultural societies with fairly dense populations.

There wasn’t a whole lot of difference in difficulty in establishing themselves on most parts of the mainland vs the islands. In Panama, the first mainland area the Spanish colonized (Tierra Firme), the native societies were at roughly the same stage of organization as on the islands, and succumbed just about as rapidly. The major factor that allowed the Spanish to conquer the natives of the Americas was disease, not whether they were agricultural societies or not.

Agreed. The flourishing Arab slave trade (which persisted well into the 20th century) argues that there was little effective resistance.

I know that the lethality of indigenous west African diseases slowed the European encroachment on Africa’s Atlantic coast. Was a similar process at work on the Indian Ocean coast?

Arab agriculture is based on wheat.

You can’t grow wheat in East Africa, because of the climate.

Therefore, the Arabs did not colonize East Africa. It’s that simple.