Ukraine's President Volodymyr Zelensky and his Polish counterpart have jointly commemorated the Poles murdered by Ukrainian nationalists in the 1943 Volhynia (Volyn) massacre.
In a Catholic cathedral in western Ukraine, Mr Zelensky and President Andrzej Duda placed candles to honour the tens of thousands who were killed.
Poland is one of Ukraine's closest allies against the Russian occupation.
But the Volhynia slaughter remains a dark cloud in their relations.
The Ukrainian nationalists, led by Stepan Bandera, operated in German-occupied Poland during World War Two and many collaborated with the Nazis. They attacked about 150 villages, murdering the minority Polish population.
Poland puts the death toll as high as 100,000 and says Ukraine should apologise and ask for forgiveness. The Polish parliament has called the massacre a genocide - a description contested by Ukraine.
The slaughter provoked reprisals from Poles against Ukrainian civilians. At least 2,000 Ukrainians were killed.
The service on Sunday was a highly symbolic gesture of reconciliation, as Russian President Vladimir Putin has repeatedly - and baselessly - branded Mr Zelensky's government Bandera-style "Nazis".
There is hardly a nation that fought in WWII that doesn’t have some dark skeletons in their closets, including Ukraine, Russia, France, Japan, China, UK, and the USA to name a few. Even genocide.
People still argue about the USA’s “genocide” over the atomic bombs. Those bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the only use of nuclear weapons in an armed conflict.
BUT... Let’s not forget that a puppet state set up by the Nazi occupiers to do their will and their will alone is a nation or the nation that once war was over, got back together. It’s a very unfair charge against the Ukrainians of today.
The Ukrainian nationalists, led by Stepan Bandera, operated in German-occupied Poland during World War Two and many collaborated with the Nazis. They attacked about 150 villages, murdering the minority Polish population.
Poland puts the death toll as high as 100,000 and says Ukraine should apologise and ask for forgiveness. The Polish parliament has called the massacre a genocide - a description contested by Ukraine.
Yup, that’s one of the “cleansing” jobs by Bandera and his like minded thugs.
They also targeted other groups
These are the ones causing all of the problems in Eastern Europe.
100,000 murdered in cold blood might be too high, might be too low, does not matter, its atrocious, enormous wickedness; extreme criminality and cruel.