A network of trade routes criss-crosses Hyboria, carrying an enormous stream of wealth to and from the four corners of the world. Trade routes are not shown on the Hyborian War wallmap. However, their pattern may be gleaned from readings of the Conan novels, spying, and from other information in your kingdom reports. Trade routes pass through seazones as well as land provinces. It is not possible to either create or abolish trade routes, and they remain unchanged throughout the entire course of the game.
Trade routes are a major source of income and therefore contention between kingdoms of the Hyborian Age. Each trade route which is established with your kingdom will automatically bring in trade revenues so long as the trade route is not successfully raided in the province where it originates. Additional income is gained from tariffs upon trade routes running through provinces under a kingdom's direct control. Tariff revenues from a province are revenues in addition to the wealth which a province normally produces and therefore enhance the overall value of controlling provinces which are centers of trade i.e. have trade routes passing through them. For example, the province of Zamboula, while not a rich province in terms of wealth production, normally provides income equal to two or three excellent provinces simply because it has so many trade routes passing directly through it.
Invasion, conquest, and battle have no effect upon the flow of wealth through
trade routes. Only raids specifically directed upon trade routes have any
effect upon the wealth they provide as income both to the kingdom controlling
the province which the trade route passes through and the kingdom to which the
trade route carries wealth.