The political tree represents the way upwards. First you´ve to apply for the lowest office in one of the first 3 chambers. An office chair is given away by the person(s) directly above. You can get the highest office of a chamber due a vote of all members. Now you can apply for one of the lower offices in the next level. Any office will give you some privileges. For example you can modify laws, the percentage of taxes, or you get immunity. There are lots of possibilities, so have a look at the lists...

Regional level (6th chamber)

Sovereign

Archbishop - Court Councillor

Grand Inquisitor - Colonel - Privy Councillor

Town Council (4th chamber)	Church Authority(5th chamber)
Mayor	Bishop
Treasurer - Judge	Inquisitor - Prefect
Customs Master - Lease Master - Building Master	Deacon - Dungeon Master - Tax Collector

Town Servants (1st chamber)	Town Bailiffs (2nd chamber)	Informants (3rd chamber)
Council Assistant	Fencing Master	Council Informer
Town Clerk	Guardsman	Informer
Town Servant - Town Servant	Night Watchman - Night Watchman	Spy - Spy

(Thanks to Quboid for all the names out of the english version)