The
Donbass or
Donbas is a historical, cultural, and economic region in eastern
Ukraine. The word "Donbass" is a
portmanteau formed from
Donets Basin (,
translit. Donetskyi basein; ,
Donetskiy bassein), which refers to the river
Donets that flows through it. Multiple definitions of the region's extent exist, but its boundaries have never been officially demarcated. The most common definition in use today refers to the
Donetsk and
Luhansk oblasts of Ukraine, whilst the historical
coal mining region excluded parts of these oblasts, and included areas in
Dnipropetrovsk Oblast and
Southern Russia. A
Euroregion of the same name is composed of Donetsk and Luhansk oblasts in Ukraine and
Rostov Oblast in Russia. Donbass formed the historical border between the
Zaporizhian Sich and
Don Cossack Host. It has been an important coal mining area since the late 19th century, when it became a heavily industrialised territory.