 Blast Furnace Bow Saw   
Chain mail Armor 
Double-bit Axe Forging   Gold Mining Horse Collar Iron Casting 
Scale Mail Armor Stone Mining Architecture   Bodkin Arrow Bracer   Watch Tower Masonry   
Plate Mail Armor Murder Hole Guard Tower Stone Shaft Mining 
Gold Shaft Mining Keep Tower 
Advance to 
Feudal Age 
Advance to 
Castle Age 
Advance to Imperial Age   ..