# Poland joins the European Union (2004)

URL: https://poland-history.com/timeline/2004-poland-joins-the-european-union
Location: Poland
Categories: main-event

On 1 May 2004 Poland joined the European Union with nine other states, the largest enlargement in the EU's history. Within the broader Third Republic period: Democratic Poland transformed its economy, joined NATO and the European Union and became one of Europe's leading states, while confronting new security challenges on its eastern border. At this point in the timeline (1 May 2004), the governing authority was Aleksander Kwaśniewski (President of Poland). Two-term president who oversaw the 1997 Constitution and accession to NATO and the EU. Poland joins the European Union mattered because it anchored Poland more firmly in the institutions of a united Europe. The event is placed here so readers can follow it alongside changes in government, warfare, society, religion and culture across Polish history.

## Why it matters
Poland joins the European Union mattered because it anchored Poland more firmly in the institutions of a united Europe.

Ruler at the time: [Aleksander Kwaśniewski](https://poland-history.com/rulers/aleksander-kwasniewski)

## Sources
- [Wikipedia — 2004 enlargement of the European Union](https://en.wikipedia.org/wiki/2004_enlargement_of_the_European_Union)
- [Encyclopaedia Britannica topic lookup — Poland joins the European Union](https://www.britannica.com/search?query=Poland+joins+the+European+Union)
- [Wikipedia — History of Poland (1989–present) (period overview)](https://en.wikipedia.org/wiki/History_of_Poland_(1989%E2%80%93present))