How about the Revolutions of 1848 so slightly better. The king of Prussia accepts the throne of Germany, but quickly moves to rollback many of the reforms wanted by the rebels. After a tense period, a second revolution occures, and the Hollerzollern king is killed, and a German Republic is proclaimed in Northern Germany. The Republicans quickly move against many of the petty German nobles, killing many and imprisoning even more.
This, naturally, draws the horror of Austria and France who invade. However, both are suffering revolutionary problems of their own. A young Saxon military officer rises through the ranks and is able to defeat the French and, later, the Austrians. With the safety of the German Republic now secure, he enters into the political scene. As the Republican's politics is filled with chaos, he quickly becomes a rallying point, and is able to assume power.
From there, he turns his attention against Austria, pushing the Habsburgs back into Hungary, and officially takes the title of Emperor. The remainder of the German states quickly fall into line, and our hypothetical Saxon general is crowned Emperor Luther I of the German Empire.
This is very off the cuff, mind you.