December 27 is Poland's National Day of the Victorious Greater Poland Uprising, a public holiday in tribute to the participants of the revolt.
The main anniversary ceremony took place in the afternoon, at the Greater Poland Insurgents Memorial in the western city of Poznań.
Officials and members of the public laid flowers in honour of those who took part in the successful insurgency against German rule.
Marek Woźniak, who heads the regional government of Greater Poland, said the Uprising of 1918-1919 had succeeded thanks to the "effort and determination of the entire Polish population of Greater Poland at the time."
Polish President Andrzej Duda issued a letter to mark the occasion, which was read out at the event.
The president said the Greater Poland Uprising constituted one of the "most glorious chapters" leading to the "resurrection of an independent Polish state."
He added the revolt of 1918-1919 would always "serve as an example for successive generations of Poles, of how to win and build a strong Poland."
Meanwhile, officials in Warsaw illuminated the facade of the presidential palace with a display in tribute to the Greater Poland Uprising.
Poland's successful 1918/1919 uprising against German rule
The Greater Poland Uprising, in which Poles rose against the German state after the end of World War I, erupted on December 27, 1918.
The revolt started after the region's German authorities opposed a visit to the city of Poznań by Polish pianist and independence activist Ignacy Jan Paderewski.
The insurgents demanded the release of Prussian-occupied Polish land as the country recovered its independence after 123 years of foreign rule.
Fighting continued throughout the region until January 1919.
The Greater Poland Uprising was one of just a few Polish insurgencies that ended in victory for the country.
Under a law initiated by the president and approved by parliament in 2021, December 27 is a new Polish public holiday, known as National Day of the Victorious Greater Poland Uprising, in tribute to the revolt's participants.
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Source: IAR, PAP, Prezydent.pl, greaterpolanduprising.eu