It’s rare for a slave population to have natural replacement, USA are one of the few exceptions. In general you need a permanent supply of new slaves to replace the low birth and high death rate.
@John7755 يوحنا came with some exception from the ancient Middle East, but while those was called slave, they sounded more like a specialized social class/caste. Such social class can be a isolated population as we as example see with the Ashkenazim in Europe, who saw relative little influx from outsider in Eastern Europe. But we also have the Romani who saw large genetic influx from neighboring populations.
In general the more control outsiders have over the women in such a population the greater influx from outside population we will see, and you can’t domestication without such control. It’s also rare for a slave master population to have a color split like in USA. Which make it harder to distinct the population from each other.
It would depend, but they were slaves by way of being property of the Assyrian monarch. They simply had a role that permitted their autonomous lifestyle when not being commanded. Generally though, slaves in Assyria were either:
-Prisoners at home. People for instance who committed crimes and fell into a slave status.
-Debt slaves. Akkadian law stipulated that people who were unable to pay debts, became slaves as a matter of course. These became chattel too, commonly, the practice was to immediately sell the debtor in order to regain your debt to someone who would use the person more readily. Most commonly, slaves were bought by rural nobles, the temples, the palace or urban merchants (especially merchants who forayed into prostitution).
-Self or familial sale. One of the most enshrined and protected systems of Akkadian law was the ability to sell you or your family to slavery. In these societies, children were assets for the family and selling excess children into slavery was common. And in times of hardship, entire families sold themselves to slavery and remained self contained slave families, whose children remained slaves and their children were slaves. Creating a growing slave population.
The rural areas of Assyria and Karduniash were inundated with such arrangements. In the middle and early Bronze Age, most peasants were freemen and farmers of their own plots. However, economic declines, famines and warfare, led to vast numbers of peasants to sell their lands and families/themselves into slavery under nobles. By 800 BCE, the common situation was large noble estates filled with large amounts of slaves who were chattel but typically were not sold due to the rooted nature of their slavery.
-Loot and pillage. This was the lifeblood of the economy in Assyria and were referred to as flocks and cattle. Assyrian monarchs were expected to take slaves every few months and donate 3/4 to the public for their free purchase.
The Itu and others, were a simple advanced version of the above and owned directly by the monarch. Their entire people had presumably been residing in Syria in 1070 BCE, but in the fall of the Hittite empire under invasions form multiple directions and most importantly from Assyrian imperialism, these people came under threat. Residing in syria, they were captured by the Assyrian kings during the Late Bronze age and their entire people were enslaved and deported to Assyria-Karduniash. Therein, they were treated as chattel under Assyrian military control and used as self reproducing military cadre, while their women and elderly worked in domestic works in the palace or by nobility who had been assigned positions in the state.
As such, the Itu could not be purchased by private citizens and were never bought, they remained a strict state monopoly and operated almost like a corevee. There are some instances wherein nobles close to the king, would request Itu for certain jobs and the contract drawn up, would be called a loan, as opposed to a purchase; the payments were made to the great king, as opposed to the Itu themselves. As such, they cannot said to have been non-chattel, but were more of an experiment of ruling and an increasingly complex outlook on slavery, society and monarchy in Assyria. The Itu were the first group to be made into a slave-caste people and were the most integrated in this system and from all that we know, were seen as paragons of loyalty, raised from birth by Assyrian bureaucrats and inundated with service to the Great Gods. Other slave castes had developed by the later Assyrian empire, such as large assortments of heavy infantry and bodyguards from Cilicia, Anatolia, possibly Greece and southern Europe and Cyprus who were forced to live in communes and stay among their group and offer their men as bodyguards for the Assyrian lords. They were prized for their stature and power in battle and in warfare, are mentioned as those who would carry the shield of the Great King.
In many ways too, we could say, the Assyrian government treated its slave warrior castes like horses. They were sometimes called cattle and state monopolies, as if they were natural resources. Horses for instance, were controlled by the state totally, it was considered impossible to purchase a horse privately for instance, one could only buy or be loaned a horse by the state or a noble. These horses too were sequestered into particular zones under state watch and control. The human slaves under direct state control, were much the same, treated as valuable resources not for the public and sequestered into communes of Assyrian watch.
I feel that in otl, the Assyrian example is the closest we get to the poster's wishes. Akkadian society, more than any that I am aware of, was based upon the dominance of slavery inundating all parts of life and interaction. The decline of slavery in the Sassanid and late Arsacid period in turn heralded the decline of traditional Akkadian religion and customs and its replacement with a more modern Mashriqi Arab culture.
