The Partition of Ostrobia was a period of history from 1482 to 1849 when colonisation of the Ostrobian Islands started in 1482 by the arrival of the British and ended in 1849 after the Ostrobian Civil War and the rise of Ostrobian nationalism. In 1620, only 10 percent of Ostrobia was by colonialists, but by 1720, 90 percent of Ostrobia was colonised by the British, French, German, Dutch, Danish and Norwegians, with the only countries: Hyenia and Stratoherra being independent. 

The conquest was due to lack of control of the Ostrobian region by smaller empires such as the Prethina, Hyenian, Stratoherran and Heyskat Empires. In 1482, British and Scotish ships began trading with the Heyskat Empire. In 1501, Danish ships began trading with the Prethina and became a protectorate. In 1503, the Heyskat Empire began recieving protection by the British. In 1510, the Heyskat Empire was annexed by the British, which angered the Danish and began annexing Prethina. Norwegians also annexed Tenarite and Holmes. In 1672, the French began colonising South West Ostrobia. In 1740, the British then annexed French South West Ostrobia. In 1743, the Dutch then annexed South East Ostrobia and founded Noelstad. In 1749, the United Front gave up and splited into Stratoherra and Hyenia. In 1751, Stratoherra and Hyenia was incorperated into the Prussian Empire.