Short answers, pulled from the story.
The world's oldest horse stables were discovered in the ancient city of Pi-Ramesses at Qantir in Ancient Egypt. They were established by Ramesses II, who lived approximately 1304-1213 BC, and could hold around 480 horses across roughly 182,986 square feet.
A stanchion barn, also called a stall barn, is a type of stable where animals are tethered by the head or neck to their individual stall rather than moving freely. It is mostly used in the dairy cow industry, though horses were historically kept this way as well.
Stables ranked as the second building on English farms because horses and working animals were vital to the economy and a direct indicator of their owner's standing in the community. These animals were highly valued and carefully maintained, making their shelter a top priority.
Traditional British stables had a hayloft on the upper floor, a pitching door at the front, symmetrically arranged doors and windows, and cobbled or bricked floors with drainage channels. An outside stone stairway on the side of the building led to the upper level, and one stall was always kept larger for a foaling mare or sick horse.
The word stable is used to describe any group of people or things managed by a single person or organization. Art galleries refer to the artists they represent as their stable, car enthusiast magazines describe collectors' cars the same way, and athletes sharing a trainer or management are regularly called a stable.
Free-standing stables began to be built from the 16th century. They were placed near the house and constructed with care because the animals they housed were expensive and economically important. Relatively few complete interiors from the mid-19th century or earlier survive today.