Archery is a tier two technology that can only be accessed after Hunting is researched. It unlocks archers, which cost 3 stars and have a range of 2 tiles. This technology also grants a defensive bonus to units on forest tiles, even if any buildings are present.
Archery expands into Spiritualism.
Since Bardur has a lot of forests, it's a wise idea to get Archery as a natural shield (if you're going defensive of course).