Macedonia (/ˌmæsɪˈdoʊniə/ ( listen)) is a geographical and historical region of the Balkan peninsula in southeastern Europe. Its boundaries have changed considerably over time; however, it came to be defined as the modern geographical region by the mid 19th century. Nowadays the region is considered to include parts of six Balkan countries: Greece, the Republic of Macedonia, Bulgaria, Albania, Serbia and Kosovo.[a] It covers approximately 67,000 square kilometres (25,869 sq mi) and has a population of 4.76 million.