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 shared monarch.
• The common Sejm, foreign and defence policy, and currency were among the areas they shared.
• Lithuania retained its own state offices, treasury, courts, legal system and army.
• The polity lasted until 1795.
• The original parchment of the Union document is held in 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, the relationship was reorganised: dynastic ties gave way to a union with shared institutions and clearly defined responsibilities. The agreement made 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 referred to as 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 Lithuania’s history, what matters is that the state became more closely united 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, was also handled jointly. These shared institutions gave the union a lasting political form. However, they 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, laws and army. This distinction is key to understanding the Union: a shared defence policy and a separately organised army are not contradictory. Similarly, common decisions could coexist with a distinct Lithuanian legal tradition. Describing the Union simply as complete incorporation overlooks these enduring institutions; portraying it as 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 its historical background, not the specific negotiations that led to it.

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

For today’s visitors, it is therefore useful not to assign visible traces too quickly to a single period. The historic sights in Vilnius and the sights in Kaunas reflect different periods in the country’s history; a building does not have to date from 1569 to help explain what came later. In museums in Lithuania, travellers can seek out historic collections and exhibitions that place political changes in a broader context.

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

The surviving document is now held in Warsaw, although 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 therefore check the archives’ current visitor arrangements separately rather than assume the document can always be seen. In Lithuania itself, the political background can be explored through several cities and collections without directly linking every present-day building to the treaty.

The Polish–Lithuanian Commonwealth lasted until 1795. Lithuania’s later history was shaped 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 us see the Union as an important, but not the only, period 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 both 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, was regulated jointly.

Did Lithuania remain a distinct political entity after 1569?

Yes. The Grand Duchy retained its own offices, treasury, courts, laws and army. Lithuanian institutions therefore continued to exist 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 equated uncritically with modern concepts of statehood and nationhood.

Where is the Union document kept?

The surviving parchment original is held in the Central Archives of Historical Records in Warsaw. Being held in an archive does not mean that the document is permanently on public display.