The Battle of Sinop was a result of the gradual disintegration of the Ottoman Empire and the loss of Ottoman force projection into the Black Sea. By 1850, the Ottoman Empire was deeply in debt and relied exclusively on British and French loans as a means of support. As a result, Ottoman leaders had no choice but to agree to drastic reductions in both Army and Navy force levels. By 1853, Tsar Nicholas I saw the reductions as an opportunity to press Russian claims in the Trans-Caucasus and along the Danube River. In July 1853, Russian forces occupied several Ottoman principalities and forts along the Danube. Mediation of the disputes broke down, and Ottoman Sultan Abdulmecid I responded with a declaration of war. Fearing Russian expansion, the United Kingdom and France issued a concurrent ultimatum: Russia was to fight only defensively. As long as Russia stayed on the defensive the Anglo-French would remain neutral, but if Russia acted "aggressively" the Western Powers reserved the right to get involved.
Hostilities began officially on 4 October, with a principal theater in Europe and another in the Caucasus. Sultan Abdulmecid ordered an immediate offensive to drive back the Russians and demonstrate Ottoman might before Ottoman finances totally collapsed. The offensive along the Danube met with mixed success, but the Ottoman attack into the Russian Caucasus was relatively successful. By the end of October, the Russian Caucasus Corps was in danger of being surrounded.
To support the attack and properly supply his forces before significant snowfall, Sultan Abdulmecid ordered a squadron of frigates, steamers and transports to establish a supply corridor to the Ottoman Army in Georgia. Unable to interdict the convoy, Russian naval elements remained in Sevastopol. Sultan Abdulmecid ordered a second convoy commanded by Osman Pasha, but by this time it was late November and the fleet was forced to seek winter quarters. The fleet ended up at Sinop, joining the frigate Kaid Zafer which had been part of an earlier patrol, and was joined by the steam frigate Taif from a smaller squadron. The Ottomans had wanted to send ships of the line to Sinop, but the British ambassador in Constantinople, Viscount Stratford de Redcliffe, had objected to this plan, and only frigates were sent.
Initial Ottoman activity in the Black Sea had been allowed to proceed unhindered, but as the situation of the Russian Caucasus Corps deteriorated St. Petersburg was forced to act. Admiral Pavel Nakhimov was ordered to muster the Russian Navy and interdict the Ottomans. From 1 to 23 November, Russian squadrons were dispatched into the Black Sea to establish control of the sea. Two Ottoman steamers, the Medzhir Tadzhiret and the Pervaz Bahri, were captured by the Russians in short engagements. Russia was able to establish operational control of the sea lanes but storms forced Nakhimov to send back most of his force for repair. Left with only a frigate, a steamer and three ships of the line, Nakhimov continued the search for Osman and the convoy. On 23 November Osman's flag was sighted returning and then entering the harbor at Sinop. Nakhimov immediately deployed his ships into a blockade and sent his only frigate to retrieve as many reinforcements as could be found.
On 30 November, Vice Admiral
Fyodor Novosiliski rallied six more ships to Nakhimov, completing the blockade force in a loose semi-circle. Additional steamers were expected, but Nakhimov decided to act before the Ottomans could be reinforced by additional ships. Osman for his part had been well aware of the Russian presence since 23 November, but felt his ships were safe in harbor. Sinop had substantial harbor defenses and forts with interlocking fields of fire and ample cannon. Osman did little to break the weak Russian blockade, even allowing many of his crews to disembark.