Type 5 Societies

Type-5 societies tend to be unstable: while the leader of a Type-4 civilization can exert direct authority over an entire kingdom, the Type-5 society has grown too large and widespread. The ruler must now rely on territorial lords and administrators, who will have ample opportunity to act in secret.

The Roman Senate was the true power in this Type-5 society. (HBO's Rome, 2005)

A society this large will be constantly hungry for resources, and will thus come into frequent contact with foreign enemies and internal rebellions. The rise of large-scale trade will result in both a newly wealthy merchant class (who will challenge the treasury's economic authority), and an influx of new ideas and technologies, sparking invention and revolution (both metaphoric and literal).

The challenge of a Type-5 society is to invent a new (more egalitarian) form of government (and the social infrastructure to support that government) that will allow it to advance to Type-6 --otherwise it will likely either collapse into civil war (Rome, Heian-era Japan, the Maya [probably], Imperial China, Westeros, Panem, and the USA), or be conquered by a more powerful neighbour (The Aztecs, Inca).

Footprint: Continent (nation-states).

Sustainable Population: Millions.

Government: Network of feudal alliances serving a central ruler or council. Unstable --leadership will change frequently, and those in power will spend most of their time and energy trying to hang onto it.

Bureaucracy: Advanced (to maintain centralized government), with each province requiring its own administrators, subordinate to the central leadership. Society is highly stratified (wealthy nobles, impoverished peasants).

Kouka's king relies on the support of the tribal leaders. (Akatsuki no Yona, 2014) 

Language: Advanced, adaptive, with local accents. Possibly used as a signifier of national identity --those unable to speak are (literally) barbarians.

Literacy: Rare and limited; rulers will employ scribes for official business, and nobles may be semi-literate.

Network: Organized city-to-city message-carrying system (probably using trained flying animals, for speed). Local mass-media (forums or town criers) may be present.

Religion: Complex and organized, possibly state-sponsored as social control (where the monarch is also given religious veneration).

Science: Alchemy begins to divide into specific fields (chemistry, biology, physics, etc). Advanced material sciences exist, including advanced metalworking using alloys. Large-scale geoengineering (building roads, dams, and leveling mountains) becomes practical, and even necessary.

Medicine: Germ theory will likely be developed, as will a rudimentary understanding of genetics. The importance of hygiene and diet are becoming apparent. Pharmacology is becoming more refined, as apothecaries arise to separate active medicinal ingredients from raw herbs. Simple prosthetics are common (hooks, peg-legs, glass eyes, etc), and simple surgeries are frequently survivable.

Education: Apprenticeship is routine for practical skills. Simple schools start to appear in cities, usually run by volunteers or religious authorities. Academies/universities may be available for the wealthy (teaching languages, history, and theoretical subjects), and may be sponsored by the government (serving to promote cultural unity rather than local identity).

A late Type-5 school in America. (Picture from Wikipedia)

Energy: Slave and animal labour remains common, along with increasingly sophisticated use of natural resources, including advanced steam engines. More advanced energy sources exist, using complex chemical reactions (distilled lamp-oil, gunpowder, simple batteries, etc), but these may not be widely available. These reactions are not self-evident, and must be "unlocked" through scientific theory and experimentation.

Industry: Powerful guilds employ many journeymen (to produce trade goods and equip the military). Artisans begin to lose influence; speed of production is becoming more valuable than quality artistry --artistically-crafted goods will be expensive, singling out the wealthy.

Military: Large and well-organized, divided into companies and platoons with specific profiles. A separate navy may be developing, relying on armed sailing ships. Possibly a distinct social class of professional warriors (no more armed peasants). These soldiers will be equipped with standardized armour and weapons, wearing the national symbol --they are a united force, not mere militias. Likely actively engaged in exploration/expansion or putting down rebellions.

Economy: Well-developed system of currency (in many denominations), with long-distance (and well-defended) trade routes to neighbouring lands and a complex system of internal roads and stockhouses to move supplies between local markets. Permanent bazaars will be a major part of most cities, and covered shopping arcades are beginning to appear. A wealthy merchant class is likely, and may be challenging the authority of the government. Piracy and banditry will be rampant; essentially becoming its own industry (incorporating fences and launderers to convert stolen goods into currency, bookkeepers to ensure equal shares, and weaponers to provide specialized equipment --the age of the "professional criminal" is at hand).

An advanced Type-5 society (and its rich merchant ships) is a golden age for pirates. (Pirates of the Caribbean: The Curse of the Black Pearl, 2003)

Food: Widespread agriculture and animal husbandry. Cooking is now standard; even slaves will turn up their noses at completely raw meat. Food preservation is becoming advanced (and the need for preservatives and flavourings will drive international trade), though all towns and villages will rely on local farms, and even large cities will be surrounded by farmland to serve the populace.

Travel: Internal roads are well-traveled (and reasonably secure) both by riding animals and by simple vehicles. Armies are likely engaged in expeditionary actions, and wealthy merchants sponsor long-range trade/exploratory missions involving massive caravans and fully-rigged sailing ships.

Spaceflight: None, though the theoretical concept may exist in fiction.

Alien contact: Hostile. This society will be wracked with internal strife and hungry for resources; any external intervention will be a destabilizing influence --these people won't be able to fly a starship, but will try to steal one. This society will be readily visible from orbit (cities, farmland), and may even be influencing its planet's atmosphere, making it detectable from interstellar distances.

Examples (reality): Inca Empire, Aztec Empire, Mayan Civilization, Dynastic Egypt, Roman Empire, Imperial China, Heian & Meiji Japan, Kingdom of England, Early USA (up until WWII).
Examples (fiction): Westeros, Eternia, Naruto's World, Hyrule, Klingons in the time of Kahless, Praxians, Ryoza, Kouka, Amestris, Equestria, Panem, Dinotopia, Mega-City One, United Republic.