How to build Siege weapons?

[TheSaint]

Can someone tell me how to get to the Engineer level 2? I want to build seige weapons?
Also I was able to conquer almost 6 castles without any "seige weapons"

[ngcsu]

you have to have a general that has the experience bonuses that allow seige weapons, and stick him in a town that has the seige building

[King Juhafin]

how can you build trade routes?

[Ulfang]

I've not needed siege weapons so far but am in the early age and a lot of cites with no defences or just with wooden walls which are pretty easy to hack your way into.

As for Trade routes you don't build them as such you just make a Knight a Merchant and select which country to trade with!