Chewa is an official language in Malawi and Zambia. It is recognised as minority language in Mozambique and Zimbabwe. Chenwa or Chichewa is known/called Nyanja in Zambia.
Chewa people pride themselves on being the largest indigenous group in Malawi. It, therefore, comes as no surprise that their language, Chichewa, has been adopted by the Malawians as the official language.
The name was officially changed from Chinyanja to Chichewa in 1968 at the insistence of President Hastings Kamuzu Banda (himself of the Chewa people).