Complex sentence: Its emperor, Napoleon III, feared that a powerful Germany would change the balance of power in Europe; opposition politician Adolphe Thiers had observed, it was France, not Austria, who was really defeated at Königgrätz.
Split into simpler sentences: Its emperor, Napoleon III, feared that a powerful Germany would change the balance of power in Europe. Opposition politician Adolphe Thiers had observed that it was France, not Austria, who had really been defeated at Königgrätz.