Which alliances get promoted to a higher league after the 4 weeks of CoP?

At the end of the event some provinces will be promoted or demoted depending on the league you are in. Those at the top will be promoted and those at the bottom can be demoted. From Silver you can only be promoted. From gold you can be promoted or demoted.

During the event you can go to the event screen and tap on the Competition ranking tab to see your current placing and at the top will be a message telling you how many of the states will be moved up or down at the end. This varies from 1 to 4.