With the exception of a very few highly favored locations around the world, hunter-gatherers never developed anything much above the band or tribe level of organization. Not a dense enought population.
So they never had kings or royal gardens. Such things show up only with agriculture.
What I find most interesting is that these finds show the early history of Europe to be much like that of the US. More advanced agriculturists moving in from the east, pushing the less-advanced natives before them or wiping them out.
The archaeologists and anthropologists never tire of postulating some time in the distant past where things were handled peacefully, but whenever actual evidence turns up it seems to indicate our ancestors were all remarkably warlike.
That's why they became our ancestors. The unwarlike or those who were insufficiently efficient at war died, killed by our ancestors.
The number of plant species domesticated by ancient American populations is HUGE and easily outnumbers the count from the Old World.
So, what you had in America were advanced agriculturalists (with, for example, squash, beans, popcorn, strawberries, and myriads of other tasty delights) being overrun by people little removed from their hunter/gather, migratory herdsman traditions.
One of the great hot-houses of agricultural development occurred in Kentucky and Southern Indiana.
The most renowned civilization, that of Sumer (the first one we know of) was started up by migratory herdsmen!
The second most renowned civilization, that of Egypt, was also started up by people who moved in from the dying grasslands of what became known as the Sahara Desert. They may have herded domestic animals, or not ~ most likely they were great hunters from the plains!
The Yayoi brought agriculture to an already civilized and organized Japan. The Jomon were developing agriculture in the far North where conditions were tougher, but otherwise they could depend on hunting and gathering in the rich hardwood forests then covering Central and Southern japan!
Dollars to doughnuts Hunter/Gatherer societies were capable of enslaving farmers and doing with them as they wished.
So, yes, "royal gardens" and filled with slaves brought in from distant lands.
We don't know where that first "royal garden" might have been but archaeologists working in Iran may well have found it ~ and are working very carefully to recover every piece of information available.
.....More advanced agriculturists moving in from the east, pushing the less-advanced natives before them or wiping them out.....
Exactly. This is a Darwinian phenomena where the strong replace the weak and take their lands. It can be said now the weak in Europe are being tested again by the more vigorous peoples of Africa. The Euros were decimated by the war and lost their will to survive