In late February 2022, Russian troops crossed the border into Ukraine, starting a war that, three years later, has become one of deadliest and most destructive in the 21st century.

Ukrainians and neighboring states and allies have watched in horror as the war unfolded. But there are surprisingly few universally agreed upon figures for the full extent of destruction. The number of civilians killed has most likely been underreported in the broad range of death toll estimates, and what official information the governments of Ukraine and Russia have released has been difficult to independently verify in the chaotic conditions of the war.

DW has surveyed data sources that systematically document the developments through transparent methodology.

After a fast offensive in early 2022, Russian troops were beaten back to southeastern Ukraine, where the war's most intense combat continues. With a "dire shortage of infantry troops" leaving Ukraine struggling to hold on to the territory it has taken back, Russia has recently begun to advance again, according to The Associated Press.

Tracking the incremental changes on the battlefield over the past three years requires combining multiple methods. The Institute for the Study of War, for example, uses satellite observations, combat footage, official military reports and mobile device location data.

Including Crimea, which Russia illegally annexed in 2014, and the eastern regions of Donetsk and Luhansk,........

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