Wilhelm I, king of Prussia, wanted to abdicate in 1862, because he couldn't get the Landtag to acquiesce to his desire for changes in the army (among other things). Albrecht von Roon suggested Otto von Bismarck as the man to force it through. Also, the Crown Prince advised against the abdication.
What if Wilhelm I hadn't appointed Bismarck, and decided to abdicate (which admittedly barring a grand piano and a safe falling on his head, I don't think he would be of a mind to do) instead. He retires to Koblenz, or a palace in Berlin with his wife, while the Crown Prince becomes Friedrich III of Prussia nearly thirty years ahead of schedule.
What if Wilhelm I hadn't appointed Bismarck, and decided to abdicate (which admittedly barring a grand piano and a safe falling on his head, I don't think he would be of a mind to do) instead. He retires to Koblenz, or a palace in Berlin with his wife, while the Crown Prince becomes Friedrich III of Prussia nearly thirty years ahead of schedule.