was an ancient province of Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, in the area of Buzen

Buzen Province

was an old province of Japan in northern Kyūshū in the area of Fukuoka Prefecture and Ōita Prefecture. It was sometimes called , with Bungo Province. Buzen bordered on Bungo and Chikuzen Provinces....

 and Bungo Province

Bungo Province

was a province of Japan in eastern Kyūshū in the area of Ōita Prefecture. It was sometimes called , with Buzen Province. Bungo bordered Buzen, Hyūga, Higo, Chikugo, and Chikuzen Provinces.-History:...

s. The ancient entity was located in modern Ōita Prefecture

Oita Prefecture

is a prefecture of Japan on Kyūshū Island. The prefectural capital is the city of Ōita.- History :Around the 6th century Kyushu consisted of four regions: Tsukushi-no-kuni 筑紫国, Hi-no-kuni 肥国, and Toyo no kuni...

 and northeastern Fukuoka Prefecture

Fukuoka Prefecture

is a prefecture of Japan located on Kyūshū Island. The capital is the city of Fukuoka.- History :Fukuoka Prefecture includes the former provinces of Chikugo, Chikuzen, and Buzen....

. It was divided into Buzen and Bungo in 683. It was sometimes called .

Emperor Keikō

Emperor Keiko

; also known as Ootarashihikooshirowake no Sumeramikoto, was the 12th emperor of Japan, according to the traditional order of succession.No firm dates can be assigned to this emperor's life or reign, but he is conventionally considered to have reigned from 71–130.-Legendary narrative:Keikō is...

is said to make Unade rule Toyo province and give him the surname Toyo-no-kuni-no-atai. This province is considered to have come under the central government at the early stage.