Was the European slave market in the East during the colonial era similar to the transatlantic slave market? If not (less brutal, etc), why?

Actually, the Eastern slave market was greater, by about 15-20%, than the Western Slave market, with total number estimated to be nearly somewhere between 14 to 15 million slaves shipped in that direction. (See *Botte: L'esclavage africain après l'abolition de 1848. Servitude et droit du sol, Lewis: Race and Slavery in the Middle East)

Undoubtedly the number is much greater than most offered on that topic (lowest I saw was 8 million, with most accepted in range of 11.5 to 14 million), as Arab slavers operated in Africa since 7th century, and we know very little about that period as there are no written native languages in Northern and Central Africa, so taking that into account number is estimated to be somewhere between 25 million to 150 million.

Which is not, in and of itself, a surprise. East was dominated, for quite a bit of the time of exploitation of Africa, by the Ottoman Empire. That and there was very active Islamic colonization of the Malay area. Additional factors were that to the West majority shipped (about 70%) were men for physical labor (with death rate during transport at 10-12%), while the East consumed mostly women and eunuchs (and survivability in that direction was estimated at less than 50%). This would also partially explain why the Western slaves' progeny is so numerous today, while in the East it's hardly noticeable and, consequently, produces false impression that East did not engage in slavery except for western colonialism.

In some Islamic states slavery was legal up until late 1960s, so I'd say the Western powers would not be the major consumer of slaves in the East. However, in some places illegal slave market is still there, either operating in the shadows (See This BBC report), or is back in some other places, like Libya, openly with open-air slave markets.

There also has to be something said about the slavery that originated in Europe. Yes, you heard it right: Europe was also source of slaves, which were then shipped to both West and East. There are no definite numbers - there seems to be a lot of information floating around which are dubious at best, citing anything between 50,000 and up to wild one million of Irish people were forcibly relocated to the American colonies and forced into indentured servitude. there was definitely some "white slave trade" going on, as cases of The transport ships Goodfellow and the Providence attests (See Robert Dunlop, Ireland under the commonwealth; being a selection of documents relating to the government of Ireland from 1651 to 1659, Volume II), when 750 of Irish women (250) and men (500) were sold in Virginia and New England. I would, after several researchers, put the number at no more than about 30,000 of Irish forced into indentured servitude in the colonies, with maybe 10,000-12,000 in North America.

Nevertheless, this still would be around 4% of the total import of African slaves into US, including colonial period. This is important, because those white slaves were more numerous than African slaves in the first 100 years of North American Colonization. I repeat, there are no reliable numbers on this topic nowhere (beyond single cases like mentioned above Goodfellow and Providence scandal), so all we have is just rough estimation. As to their condition - they were treated somewhat harshly and not until 1782, their lot improved, when the indented servitude was legally required to be confirmed by contract in writing, with witnesses. They were much better off than actual slaves, though and of course.

On the other hand Islamic conquest of much of the Med and relentless attacks on the rest of the West (which would stretch for nearly eleven centuries) may account for similar number of slaves shipped to the Middle East from almost all of Europe as total number extracted from Africa. How much of the West we're talking about? Well, Muslim slavers operated as far north as Iceland... For example, there is the case of

the people of the town of Baltimore in Ireland, all carried off by ‘corsair’ raiders in a single night

(See Christopher Hitchens: Jefferson Versus the Muslim Pirates, City Journal, Spring Issue, 2007).

Again, East consumed mostly women and eunuchs, which again would carry very high mortality along the way (See Giles Milton: White Gold and Robert Davis: Christian Slaves, Muslim Masters). Estimates are that this brought about 1,500,000 slaves, and of these almost 5000 a year, over the span of three centuries, where sailors captured by just Berbery pirates preying on shipping. Miguel Cervantes was one of these, however he was ransomed.

If we add Tartar raids and invasions of the Eastern Europe (Russia - Crimea - Ukraine - Poland - ) the numbers could be even greater. The estimate is that about 6,750,000 slaves were sold by Tartars between 1350 and 1700 (See Erdem: Slavery in the Ottoman Empire and Its Demise, 1800-1909, Fisher: Muscovy and the Black Sea Slave Trade, Inalcik:An Economic and Social History of the Ottoman empire, Khan: Islamic Jihad: A Legacy of Imperialism, Forced Conversion and Slavery)

As to the brutality of the slave trade and the slavery overall it's not as simple as it sounds. Yes, casualties among the captured slaves were high, and they remained so up until slave abolition in the "West". It was common knowledge, even back then, that cramming a lot of people into wet and hot cargo holds, without adequate food and drink, would inevitably lead to disease and death. But especially during age of sail the supplies were limited - as they had to be, there is limited capacity on a ship, so an even minor deterioration of the sailing conditions led to bad situation aboard. Also, there were realities that can't be ignored: sea voyage was dangerous, not just for the weather. Also, slaves were valuable commodity and it is quite common on slave ships for medical personnel (if there was any), to receive bonuses if deaths were kept low. Mortality among passengers and crews plying the Atlantic routes was also considerable.

In 1789, William Wilberforce in his speech opening the parliamentary debate on the slave trade estimated that cost of slavery was as high as 50% mortality just due to Middle Voyage - 12,5% in transit, 4,5% on shore awaiting sale and 33% during acclimatization year, getting used to the new continent. Compare that 12.5% with 8% death rate for German colonists sailing to Pennsylvania (or British criminal convicts bound for the New World) and it is still a stark contrast, but not quite exceptional. (See Klein et al: Transoceanic Mortality: The Slave Trade in Comparative Perspective [Author also suggest that departure and destination points are important: that had the European colonists departed from Morocco and were bound for Brazil, their death rates during voyage would be much higher, too. In fact, the port of departure was the most determining factor in the transport death rates, sometimes doubling it compared to other embarkation points, like Bight of Biafra]) Then compare that to slave ship crews: it was at lower levels, but not that much in some cases. As a rule crew replacement ratio on - for example - Dutch ships was over 40% YoY (but that probably includes voyages to Indonesia). It is worth pointing out that overall average number is average - only when one starts drilling down some knowledge can be gleaned, and every researcher who ever did some work in that topic cautions that no two trips are the same and most of them were "low-incidence", it is when something goes bad there's a disaster. In other words: on majority of the trips when slaves were transported there were few deaths, but it was the outbreaks of some sickness or it takes longer than usual and food and (especially) water runs out. Then there will be much more death.

Sex slavery was also a part of the Atlantic trade, but it sought mostly mixed-race women and in that case most desired was educated mixed-race woman. Here implications are unthinkable and they are: that specific set of requirements meant that those women were literally bred for the purpose of sex slavery and it also may mean that it may actually have been "domestic", rather that Africa-originated.

But that's Western direction. Compare that to Eastern direction and you will find completely different story for the most part.

Yes, there was a slave labor market part in there, but same considerations apply and we're talking here about overseas dominions of European states, which were not as desperate for manpower. That's not to say there was no slave trade - Dutch VOC is said to be responsible for about 1 million people shipped to Dutch East India Company's holdings in Oceania, with same problems as the South America - bound slave trade, but the slaves came from different areas, like Bali, Borneo, Bengal, Madagascar, China... But mainly it would be "local source" - same as Africa, warring tribes and kingdoms would sell captives of the side that lost (See Matthias van Rossum: Colorful Tragedy: The history of slavery in Asia under the VOC)

The rest... The rest was, one can safely say, completely different purpose for slaves, and the destination was mostly territories of the Islam, with interest in mostly pleasure slavery. And eunuchs. Considering that this market absorbed a lot more slaves (in total, from all sources, including Europe, it could easily be twice that of Western route or more), the fact that there's very little evidence of it now, among populations of Middle East and Mediterranean, tells volumes about it's brutality.

First of all, in another contrast to West, East procured mostly women. If they were men, then mostly they were castrated after purchase. Just this operation accounted for 50% casualties among male slaves (and could go as high as 90% - see Lovejoy: Transformations in Slavery). Skilled slaves - craftsmen, educated men and soldiers - were also sought, but majority of the trade was sexual, so mostly young women and young boys. According to some accounts, in 19th century, mortality rate for East trade route was 75-80% (See Gann & Duignan: The Rulers of German Africa 1884- 1914). It's hard to imagine it better in previous period. [This would be the central point of the 150 million estimate: if just 20% survived to the selling block, then this sounds about right]

Sex slavery was so widespread that it became central policy of almost all Islamic states, with Ottoman Empire as most visible example. Indeed, it was banned permanently (because it was banned formally a few times before) just before end of XIX century, and continued as black market for few more decades.

There is a reason that, in stark contrast to Americas, Middle East bears almost no traces of that slavery today. How is possible that descendants of those Americas bound slaves constitute between quarter and a third of the total population? And bear in mind that majority of them were males, so reproduction rates would be initially very low.

Now, there must be raised the point of the treatment of slaves. There is no doubt that slaves in - to use a most basic distinction - Christendom didn't have it great. They were there mostly for manual labor, so neither their welfare nor education nor prosperity were high on the list of their owners. Or lords, in case of indentured servitude incl. serfdom, but this is somewhat special case. For example Polish state(s) relied heavily on serfdom far longer that rest of the civilized world, but even there and then it was far better than slavery in the west and Islamic sex slavery wasn't even in the shouting distance. There are historical accounts (See: Lewis: Race and Slavery in the Middle East), that mention the frightful conditions of slaves in Egypt, where

I have heard it estimated that five or six years are sufficient to carry off a generation of slaves, at the end of which time the whole has to be replenished. [carry off = die off, which means 100% death rate within 5-6 years]

But similar stories could be found in mines or plantations of Brazil, where average life expectancy of a slave was as low as 2 years in mines and 7 on plantation, with places having replacement rate of 100% over the period of 7-10 years.

On the other hand slaves in Islam often could attain positions of influence and/or of authority (if latter much rarer, as this is forbidden by the Qur'an), and accepting Islam was always the fastest way out of slavery, especially for men. Mamelukes are a prime example of slaves in a position of prestige. It is safe to say that, in some Islamic countries, some slaves were better off than in the west.

However, there is very important point to be made here: regardless of the direction they were shipped to, both Atlantic and Eastern slave trade was ALMOST EXCLUSIVELY Arab in origin. That is: slaves bound for plantation in Louisiana in North America was bought from Arab slaver 999 times out of 1000. They, in turn, got much of those slaves from kings and chiefs of the more successful tribes, who won the war against other tribes.

But that also carries the following: had it not been for the demand, the supply would not be there. So West's culpability in slavery means it's directly responsible for big part of all that death in Africa, where most wars between African kingdoms, tribes and clans were fought explicitly for slaves.

Last point to make is this: It is very curious that slavery in Islam is compared to slavery/serfdom/indentured servitude in Judeo-Christian world, but it explicitly excludes dhimmitude, which was in essence another social level that is usually considered as bottom of a social structure and members treated accordingly. Because if we include that, then there's no comparison, really, between the scale of the two.