The Ammonite Galaxy, a fairly typical spiral galaxy somewhere, is part of a small local group of twenty galaxies, which in turn is part of a large cluster, known to the Sellites as the local cluster.

It is a long way away from the Milky Way galaxy, some various billions of light years at least. Nobody who lives in the Ammonite Galaxy knows anything about the Milky Way, except that it is a typical spiral galaxy with a relatively small supermassive black hole at the middle, in a fairly large cluster which forms part of the Great Magnetizer, as the Sellites call it. The Great Magnetizer is definitely not the Virgo supercluster.

The Galaxy is divided into five general areas, all radiating outwards from the supermassive black hole at its center.  These are known as the Quintiles.

The distances involved are huge. Pictoris is 30,000 light years from the binary system, and Enara is 100,000 light years from Valhai and 90,000 light years from Dessia.(They come into the later books)

Three stars are in orbit around each other. Since one of them is a failed star, Nomus, the inhabitants of the system refer to it as a binary system ignoring the star they can hardly detect.

The other main star is called Sacras, and has three planets in orbit around it. Coriolis is the nearest, Kwaide the next and then a massive gas giant called Lumina. Both Coriolis and Kwaide support life and have large populations.

Valhai is a small planet which is in orbit around Almagest, a red dwarf star in the Ammonite Galaxy. It forms a nearly perfect equilateral triangle with Almagest, and a big planet, Cian, also in orbit around Almagest.

Valhai occupies what is known in Astronomy as the Lagrange 4 spot, or L4. There are two small planets in orbit around Cian, Xiantha and Cesis, both with intelligent life, which developed naturally.

Of the other planets, Xiantha and Cesis, in the Almagest system, are by far the most developed. Cesis, the Sellites original home, is technologically advanced. Xiantha has had access to that technology, but has remained rather more primitive in its customs. The Xianthans are proud of the Xianthes, a natural phenomenon which is considered to be the most overwhelming experience in the whole system. This is lucky, as Xiantha is relatively backward as planets in the system go, and the Xianthes have enabled them to create a booming tourist industry. Otherwise the Xianthan lowlanders are famous for their vibrant paintings, full of colour and movement. These paintings do not have a particularly high intrinsic price, but have become popular amongst tourists.