While the churches eventually worked out their differences and came to an initial agreement, both Nicholas I of Russia and Napoleon III refused to back down. Nicholas issued an ultimatum that the Orthodox subjects of the Empire be placed under his protection. Britain attempted to mediate, and arranged a compromise that Nicholas agreed to. When the <answer>Ottomans</answer> demanded changes, Nicholas refused and prepared for war. Having obtained promises of support from France and Britain, the <answer>Ottomans</answer> officially declared war on Russia in October 1853.
Who demanded the changes that Nicholas later refused?
Ottomans