Inge Nielsen, Hellenistic Palaces: Tradition and Renewal

On the basis of the sources, nine main groups of functions may thus be distinguished, which, however, need not all be present even in a royal palace, and still less in other kinds of palaces... These functions were served and supported by a considerable number of halls, rooms, and buildings:

1. Official and ceremonial functions required reception and audience halls, as well as council halls and courtrooms; these all needed to contain a throne and had to be spacious, since the king’s Friends, as well as his guard, were normally present on such occasions. All these official activities probably often took place in the same hall, which at the same time served as a throne-room, although it might be expected that receptions demanded more space, and thus frequently took place in the open.
2. Social functions were primarily served by banqueting halls. Here, the king could meet his guests and subjects and display his munificence. These banquets frequently followed audiences, and undoubtedly the same hall was often used, at least for large dinner-parties, since movable klinai and tables were common items of furniture. For minor parties, including drinking-parties, smaller halls were called for, while very large banquets could be held in the open or in temporary buildings.
3. Religious functions demanded the construction of dynastic sanctuaries, temples for tutelary deities, and often mausolea.
4. Defensive purposes were primarily served by city walls and citadels, but also, for example, by barracks for the all-important royal guards.
5. For administration, the provision of archives, offices, and treasury was a requirement. In the Hellenistic period, the archives were separate from the library, in contrast to the Assyrian palaces, for example.
6. Service functions were represented by kitchens, storerooms, living-quarters for the servants, etc.
7. Residential buildings for the king, his family, his guests, and often his court always formed part of the palace.
8. “Public” institutions such as theatres, libraries, palaestrae, hippodromes, etc., were frequently, but not always, present in the royal palaces.
9. Basically recreational elements, including gardens and parks, pavilions, (swimming-)pools, and game reserves, played an important role in royal architecture. Such parks could also be used for official purposes: for example for large receptions and banquets.

Inge Nielsen, Hellenistic Palaces: Tradition and Renewal
(Studies in Hellenistic Civilization, Vol. V, pp. 25-26.
Aarhus University Press, 1999)