 Complete the following phrase:  In some regions of modern-day Croatia, mainly in southern Dalmatia, ethnic Serbs have been present from the Early Middle Ages. Serbs from modern-day Serbia and Bosnia-Herzegovina started actively migrating to Croatia in several migration waves after 1538 when the Emperor Ferdid I granted them the right to settle on the territory of the Military Frontier. In exchange for land and exemption from taxation, they had to conduct military service and participate in the protection of the Habsburg Monarchys border against the Ottoman Empire. They populated the Dalmatian hinterland, Lika, Kordun, Banovina, Slavonia, and Western Syrmia. From the beginning of the 20th century, the Croat-Serb Coalition led by Croat Frano Supilo and Serb Svetozar Pribićević governed the Kingdom of Croatia-Slavonia until the dissolution of the Austro-Hungarian Empire. After the creation of the Kingdom of Serbs, Croats and Slovenes in 1918 later renamed to Yugoslavia, a few thousand Serbs moved to Croatian territory. During World War II, Serbs were targeted for extermination as part of 