May 3 in Poland is a public holiday which celebrates a historic constitution that legislators adopted on May 3, 1791.
The presidents of Lithuania, Latvia, Estonia and Ukraine were invited by Polish President Andrzej Duda to celebrate the anniversary at the Royal Castle in Warsaw.
The leaders are also expected to discuss the future of Europe and sign a joint declaration after the meeting in Poland’s capital.
The pioneering Polish constitution of 1791 is described by historians as one of the proudest achievements in the nation’s history.
The historical document was the first modern constitution in Europe and the second worldwide, after the American Constitution, which was created in 1787.
But reforms and liberties proposed in the document – including religious tolerance and the separation of powers – were viewed with suspicion in neighbouring countries, especially in light of the French Revolution raging at the time.
The Polish reforms were seen as a threat to the European status quo by Russia, Austria and Prussia, historians say, and the adoption of the constitution hastened the dismemberment of Poland by those powers.
After a series of partitions, Poland in 1795 lost its sovereignty for 123 years. It re-emerged as an independent state on November 11, 1918, the day World War I ended.
While Poland marks Constitution Day on May 3, Independence Day is on November 11, commemorating the restoration of the nation’s sovereignty.