A royal succession dispute opens the way to war

Frederick VII's marriages produced no heir, leaving rival branches of the royal family to contest the succession. German interests supported the Augustenburg line, while most Danes favoured the Glücksburg claimant who became Christian IX. Christian's earlier service on the Danish side in the First Schleswig War made him more acceptable in Denmark. The Augustenburg family, by contrast, was regarded there as strongly pro-German. An Augustenburg king was unlikely to surrender the Danish crown to a greater Germany, but the choice could have pulled Denmark firmly into the German political orbit. The disputed succession thus supplied a political trigger alongside the linguistic, national, commercial, and strategic pressures already surrounding Schleswig-Holstein.