Final answer:
To gain the support of northern Germans for unification, Otto von Bismarck engaged in wars and used Realpolitik to expand Prussian dominance and appeal to nationalist sentiments, culminating in the unification of Germany under Prussian leadership in 1871.
Step-by-step explanation:
To gain the support of northern Germans for unification, Otto von Bismarck initiated a series of diplomatic and militaristic strategies aimed at consolidating Prussian power. He focused on building a powerful, authoritarian state that appealed to the interests of the Protestant north and orchestrated wars that demonstrated Prussia's dominance. These wars included conflicts with Denmark, Austria, and France, and resulted in significant territorial gains such as the duchies of Schleswig and Holstein, and the Franco-German territories of Alsace and Lorraine.
Realpolitik played a crucial role in Bismarck's methods, as he prioritized practicality and pragmatism over ideology when making political decisions. His employment of Realpolitik notably influenced the decision to annex the northern German states and to ally with southern German states against French imperialism, therefore strengthening the momentum towards unification. Bismarck's adept manipulation of nationalism also helped inflame popular support for his policies.
Finally, through the manifestation of his Realpolitik approach, Bismarck succeeded in keeping Austria out of contention as a governing power for a unified Germany without attempting to conquer it. This strategy was part of Bismarck's comprehensive efforts that eventually led to the proclamation of the German Empire in 1871 with the Prussian king as its emperor.