Donbas, Ukraine's ravaged heartland, has suffered eight years of warfare. Here's why Putin wants it

Donbas, a sprawling and beleaguered heartland region that blankets much of eastern Ukraine, has been the front line of the country's conflict with Russia since 2014.

But now its people, already scarred by eight years of fighting, are bracing for an assault even more intense. An impending battle for control of the territory is expected to define Russian President Vladimir Putin's invasion, after his forces suffered costly failures in Kyiv, and across central and northern Ukraine.

Satellite images have shown Russian military convoys and resupplied units moving towards Donbas for a large-scale offensive, and Ukraine's foreign minister has warned the world of an impending battle there that will "remind you of the Second World War."

A Russian victory in the region would appall the West but could salvage Putin's war aims, while a defeat could cement his invasion as a historic failure. Either way, it is almost certain to devastate yet more of the Donbas region, a historically and culturally significant place whose proximity to Russia has dictated much of its turbulent existence.