Explained - Why Vladimir Putin invaded Ukraine
2014: Pro-Russian government in Ukraine was overthrown, pro-West regime comes in
2014: Russia invaded and annexed Crimea, a peninsula that was part of Ukraine
2021: Ukraine, a former Soviet Republic, says it wants to join NATO
Riled up Putin asks West for a guarantee that Ukraine won't join NATO
Putin starts amassing thousands of troops on Ukraine border as tensions rise
Also watch: Ukraine Crisis: Missiles, tanks, explosions - watch the latest videos from Russian attack on Ukraine
Hectic diplomatic efforts and talks between Russia and Western countries
Feb 21: Putin recognises 2 separatists' regions in East Ukraine as independent nations
Feb 22: Rebel leaders seek Russian military help against Ukraine army
Feb 24: Putin clears military action inside Ukraine, Russian troops move in
Also read: Ukraine Crisis Live Blog