Introduce the Presbyteries is a Decision unique to 
Hannover.
It requires that Hannover is not a puppet of 
United Kingdom and that it has a militancy of at least 3.0. Hannover will start the game as a puppet of United Kingdom, but will break free after the event Coronation of Queen Victoria.
The decision lowers militancy of all 
Protestant POPs by 1.0. At the beginning of the game 88% of the population is Protestant.
Ingame-text: In 1848 The Kingdom of Hannover strengthened popular representation within the Lutheran State Church by the introduction Presbyteries, popular elected church boards charged with administrating church affairs.