Kastamonu Province is one of the provinces of Turkey, in the Black Sea region to the north of the country. It is surrounded by Sinop to the east, Bartın, Karabük to the west, Çankırı to the south, Çorum to the southeast and the Black Sea to the north.
It is not definitively known when Kastamonu was first founded. However, some sources dating back to the Early Middle Ages refer to the province. There are also some archeological findings that date to about 100,000 years that suggest the region was inhabited at that time.
With the weakening of the Macedon kings, the Paphlagonia and Bithynia regions were engulfed by the newly formed Pontus kingdom. After the fall of the Pontus kingdom in first century BC, the area was incorporated by the Roman Empire by joining Paphlagonia with Bithynia. The capital center of this new city-state was Pompeiopolis, of which the remains still stand near Tasköprü District in Kastamonu.
The region then fell under the hegemony of the Seljuq dynasty (11th century CE), followed by the Danishmends, the Byzantines during the crusades, Çobanoğlu and Jandarid beyliks. The Ottoman sultan Beyazid I conquered the province in 1392; however, following his capture and death in Battle of Ankara, the area was granted back to the Çandaroğlu by the Mongol warlord Timur Lenk. Ottoman sultan Mehmed II incorporated the region back into the empire in 1461.
During the Ottoman reign, the province boundaries were expanded up to reach Constantinople. The sultan's heirs were often sent to rule the province as governors to gain experience.
After the First World War, during the battles of the Turkish War of Independence, Kastamonu played an important role in the supply of ammunition and troops to the İnebolu–Ankara front, transporting the war machines that would arrive to İnebolu by sea from Istanbul (Constantinople) and the Soviets. When the Greeks noticed this activity, the İnebolu port was bombarded from the sea on 9 June 1921.