Simplify the following text for a Grade 10 native English-speaking person.
Original: Zimbabwe ( ; officially the Republic of Zimbabwe and formerly Southern Rhodesia , Rhodesia , the Republic of Rhodesia , and Zimbabwe Rhodesia ) is a landlocked country located in the southern part of the African continent , between the Zambezi and Limpopo rivers .
Simplified: Zimbabwe was known as Rhodesia when it was a colony of Great Britain , but it took the ancient name of `` Zimbabwe '' in 1980 when it became an independent country .