A landlocked, rural nation in southern Africa, Swaziland has significant problems. Nearly a third of the country’s population lives in extreme poverty, and about as many are infected with H.I.V., one of the world’s highest prevalence rates for the virus. Life expectancy is low, around 50. A recent drought and an infestation of armyworms, an invasive species, devastated crops.

So the kingdom’s 1.4 million residents might have been surprised on Thursday when King Mswati III, one of the world’s few remaining absolute monarchs, announced the news: The country will henceforth be known as eSwatini, the kingdom’s name in the local language. (It means “land of the Swazis” in the Swazi — or siSwati — tongue.)

The king, who has reigned since 1986, announced the name change — an adjustment, really — during a ceremony in the city of Manzini on Thursday to mark his 50th birthday.

Many African countries upon independence “reverted to their ancient, native names,” The Associated Press quoted the king as saying. “We no longer shall be called Swaziland from today forward.”