The Union of Lublin and the Polish–Lithuanian State

• The Union was agreed in Lublin on 1 July 1569.
• It united the Kingdom of Poland and the Grand Duchy of Lithuania in a common republic.
• Both sides elected a common monarch.
• The common Sejm, foreign and defence policy, and currency were shared areas.
• Lithuania retained its own state offices, treasury, courts, legal system and army.
• The polity lasted until 1795.
• The parchment original of the Union document is held at the Central Archives of Historical Records in Warsaw; it bears 78 seals.

Poland and Lithuania had close ties even before 1569. A dynastic personal union linked their ruling houses, while the two political entities retained their own structures. In the 16th century, this relationship was reorganised: dynastic ties gave way to a union with shared institutions and clearly defined responsibilities. The agreement reached in Lublin was therefore more than a marriage or alliance treaty, but it did not simply dissolve Lithuania into Poland either.

The new republic is often called the Polish–Lithuanian Commonwealth or the Republic of the Two Nations. These names describe the political order of the time; they do not automatically mean two nation-states in the modern sense. For Lithuanian history, the key point is that the state became more closely integrated without merging all its institutions. The Union established shared decision-making while leaving room for Lithuanian responsibilities to continue.

The monarch was jointly elected by nobles from both sides. The Sejm served as a common parliament, and foreign and defence policy, as well as the currency, were also handled jointly. These shared structures gave the union a lasting political form. However, this did not mean that all administrative systems or military units were merged into a single authority.

The Grand Duchy of Lithuania retained its own state offices, treasury, courts, legal norms and army. This distinction is essential to understanding the Union: a shared defence policy and a separately organised army are not contradictory. Likewise, common decisions could coexist with a distinct Lithuanian legal tradition. Describing the Union simply as complete incorporation overlooks these enduring institutions; calling it a loose alliance fails to recognise the shared bodies.

This political development had a long prehistory. The early stages of Lithuanian state formation can be traced through Mindaugas and the later rise of the Grand Duchy under Gediminas. These centuries preceded the Union; they explain the historical background, not the specific negotiations that led to it.

The Union brought the two parts of the polity into closer political and cultural contact. But this does not mean that Lithuanian symbols or every distinct political tradition disappeared. The perspective of a modern nation-state only partly applies to an order in which rulers, nobles, towns and regions had different rights, languages and religious ways of life. Society within the Grand Duchy itself was also diverse.

For visitors today, it is therefore worth avoiding the assumption that visible traces belong to just one period. The historic sights in Vilnius and the sights in Kaunas reflect different chapters of the country’s history; a building need not date from 1569 to help explain what happened later. At museums in Lithuania, travellers can look for historical collections and exhibitions that place political changes in a broader, longer-term context.

The Union document is itself a remarkable historical record. The Central Archives of Historical Records in Warsaw describes the surviving parchment original as the Lithuanian copy intended for the estates of the Polish Crown. Written in Polish, it bears 78 seals belonging to senators and deputies of the Grand Duchy. According to Poland’s Ministry of Culture, the Polish counterpart intended for the Lithuanian side has not survived. Details like these show that the Union was not merely an abstract treaty of state, but was also documented in actual written records and involved the participation of political representatives.

The surviving document is now kept in Warsaw, while the Union was agreed in Lublin; its presence in the archives does not mean it is permanently on public display. Anyone planning a trip should check the archives’ current visitor arrangements separately rather than assume the document can always be viewed. In Lithuania itself, the political background can be explored through several cities and collections, without treating every present-day building as directly connected to the treaty.

The Polish–Lithuanian Commonwealth lasted until 1795. Lithuania’s later history was marked by further political upheavals, including Lithuania under the Russian Empire, the independent Republic of Lithuania from 1918 to 1940, and the subsequent occupation, resistance and restoration of independence. These chapters came centuries after 1569. They help put the Union in perspective as an important, but not the only, phase in a long and eventful history.

When and between whom was the Union of Lublin concluded?

On 1 July 1569, the Kingdom of Poland and the Grand Duchy of Lithuania agreed to the new Union in Lublin. It brought the two political entities into a shared political framework.

What changed as a result of the Union?

Both sides gained a jointly elected monarch and shared political institutions, including the Sejm. Foreign and defence policy, as well as the currency, were governed jointly.

Did Lithuania remain a distinct political entity after 1569?

Yes. The Grand Duchy retained its own offices, treasury, courts, legal norms and army. Lithuanian institutions therefore continued alongside the shared institutions.

Was the Union the same as a modern Polish–Lithuanian nation-state?

No. It was a political union between the Kingdom of Poland and the Grand Duchy of Lithuania within the European order of the time. The term “Republic of the Two Nations” should not be uncritically equated with modern ideas of states and nations.

Where is the Union document kept?

The surviving parchment original is held at the Central Archives of Historical Records in Warsaw. Being kept in the archives does not mean the document is always on public display.