Answer:
Conquest of Constantinople by Great Britain and France in the Crimean War.
Step-by-step explanation:
The decline in the ottoman empire was a long process caused by a decline of competence within the ruling family , Internal decay of the ruling elite, The Europeanization of the Turkish upper class and a decrease in the involvement of the rulers in the activities of the government. The crimean war had few impact in this since this war was against russia's expansive policy. Great Britain, France and the ottoman were allies in this conflict