Can't build new barracks :S (Roma)

Just finished colonising southern Italy, both cities got Level 1 Government (I've only just started the campaign). I destroyed their Greek barracks because they weren't letting me do anything, but now only have Levy support options for local soldiers :S

How do I get the normal barracks (Campus etc.) available to me? Do I need Guardposts or something, or just keep upgrading local support buildings? Thanks! :D

P.S

Barracks aren't in the Building Browser :S

You cannot build factional units in that area until the Polybian reform. And not outside of Italia until the Marian reform.