“To confront one's own history, to dare looking at the facts as they are, to not evade one's own guilt, one's own failure is an inter-generational process,” Gauck said during his speech.
“We, who want to understand how our fathers and grandfathers became murderers and victims, rely on each other today.”
The President's five-year-tenure, which is due to end in 2017, has been marked by his effort to commemorate Germany's dark past, as he has undertaken eight trips abroad in the spirit of reconciliation and paid tribute to the Nazi's victims in several speeches.
A mass execution at the ravine of Babi Yar
The Nazis and local auxiliaries murdered tens of thousands Jews between September 29th and 30th of 1941 as they blitzed their way toward Moscow and captured major cities on the western Soviet flank.
In an interview with AFP, Raisa Maistrenko, the last survivor of that tragedy still alive in Kiev, stated that Jews comprised about a quarter of the city's 800,000-strong population at the time.
"We were gathered and sent along 'the path to death'," she recounts.
"All the Jews decided to go because they thought they would be evacuated by train as the railway station was nearby. Nobody could possibly assume there would be a mass execution.”
But with the help of her grandmother, Maistrenko was able to escape her impending fate.
"We heard the shooting behind us, but [my] granny - she kept holding me - did not look back and kept running until she fell exhausted among the graves in a nearby cemetery," she said.
Most of the rest were brought to the ravine of Babi Yar close to the city, and by the end of the next day, the Nazis had killed nearly 34,000 people.
A question of responsibility
"No Ukrainian has the right to forget this tragedy," Ukrainian leader Petro Poroshenko told a commemoration at which children played a concert honouring the victims.
But the Israeli President Reuven Rivlin also called attention to Ukraine's role in the massacre, since members of the Ukrainian Insurgent Army (UPA) initially collaborated with Hitler's generals.
German President Gauck also said that Nazis "even used nationalist Ukrainians as assistant police."
"But we also admit that not only special fences [of death camps], but ordinary Wehrmacht soldiers were involved in these crimes.”
And New-York based World Jewish Congress chief Robert Singer went even further, urging at Babi Yar for "all the countries involved, not just Ukraine, to take responsibility for their actions during that dark time".