1. German nationalism developed in response to the spread of the German language during the Protestant Reformation led by Martin Luther.
2. German philosopher Johann Gottfried Herder further developed ideas of German nationalism based on principles of collective self-determination and cultural identity.
3. After failed attempts to unify Germany in the 1840s, Prussia achieved dominance over Germany through military victories over Denmark, Austria, and France, leading to the founding of the German Empire in 1871.