Poland marks the 85th anniversary of the outbreak of the Second World War with a ceremony in Wielun - one of the first Polish towns to be bombed by the Nazis on 1 September, 1939.
President Andrzej Duda says that Poland learnt its lesson from the war and can no longer afford to be defenceless when next to an imperialist neighbour, referencing Russia.
He also stresses that German war reparations to Poland continue to be owed.