Can't build Seige Workshop

[Kemaria]

I've played 2 games now where I get to the castle age and cannot build a seige workshop the option doesn't even show. I have all the requirements?

[WSlord]

For most nations it requires a blacksmith and the siege workshop will not show until the blacksmith is built.
Some custom and campaign scenerios also prevent you from building them (more common to the Forgotten).

Hope that helps.

[FiftyTifty]

Generally, when you are in Feudal, you should have >27 villagers as soon as you started to advance from the Dark Age. Once you're in Feudal, build a market and a blacksmith, then click up to castle age.

[Xinnobun]

Just like the market requires a granary first, the siege workshop requires the blacksmith first.