2 October, 21:17
On Res Unita. Poland and Ukraine: Fifteen Centuries of One History
The history of Polish-Ukrainian relations is usually written from two separate desks. For Polish historiography, Rus' was the eastern borderland of the Crown and the Commonwealth. For Ukrainian historiography, Poland was an empire from which Ukraine fought for its independence more than once. The two accounts meet mainly at points of conflict: 1648, Lviv in 1918, Volhynia in 1943, Operation Vistula in 1947. Between those points the story swings between two convenient schemes, eternal enmity and eternal friendship. The first serves memory politics, the second serves diplomatic speeches, and neither describes what actually happened.
The years 2014-2022 made this especially visible. People were growing closer: Ukrainians moved to Poland by the million, visa-free from June 2017, and surveys recorded rising mutual sympathy year after year. At the same time memory was at war, with disputes over monuments, laws on historical memory and a moratorium on exhumations. This leads to the question with which Res Unita begins: what changes if the history of Poles and Ukrainians is written not as the history of two neighbours, but as the history of one people that split into two?
The beginning lies in the ground
I begin the book not with a political thesis but with what lies in the ground. On September 3, 2025, the journal Nature published a study by Joscha Gretzinger, Felix Biermann, Hannes Mager and several dozen co-authors from the Max Planck Institute for Evolutionary Anthropology in Leipzig. They analysed 555 ancient genomes, 359 of them from Slavic burials. It turned out that in the 6th-8th centuries settlers from Eastern Europe replaced more than 80% of the earlier population in eastern Germany, Poland and Croatia. They came from the area between the Dniester and the Don, or, as the institute's press release put it more precisely, from between southern Belarus and central Ukraine. On the same day Genome Biology published a Czech study of 18 genomes from South Moravia with the same result.
What does this mean? Genetics does not make Poles and Ukrainians one nation, and the book says so plainly: nations are made of language, faith and shared memory, not haplogroups. But the question of origin is closed. Poles and Ukrainians share a common origin, and anyone who claims otherwise today is making a political statement, not a scientific one.
Archaeology and language say the same thing. The Prague-Korchak culture has a double name because a pot from near Prague cannot be told apart from a pot from near Zhytomyr. According to Czech analyses, about 70% of early Prague pottery belongs to the type that Iryna Rusanova called Korchak in the 1960s, and its oldest forms come from the Dnipro region. The oldest Slavic river names lie in northwestern Ukraine, and river names change more slowly than anything else in a language. Calling these people Ukrainians is wrong, and calling them Poles is just as wrong. What is right is that they cannot be divided into two nations.
One construction, used twice
In the introduction I examine a story that Polish and Ukrainian scholarship usually treat separately. In the 18th century, German scholars at the St. Petersburg Academy of Sciences built the Normanist theory, according to which the state of Rus' was created by Scandinavians. Gottlieb Siegfried Bayer derived the name "Rus'" from Scandinavian languages in 1729, Gerhard Friedrich Müller declared the Varangians Swedes in 1749, and August Ludwig von Schlözer wrote that before the Norsemen the Slavs lived like wild beasts and birds. In 1938, Hans Jänichen applied the same scheme to Poland: from the name "Dagome" in the Dagome iudex he declared Mieszko I a Scandinavian.
The answer came from Polish scholarship, and it answered for both. Józef Kostrzewski refuted Jänichen with archaeological evidence in 1939. In 1957 Henryk Łowmiański published a study of the role of the Norsemen in the origins of the Slavic states, not only the Polish one, and showed that in Poland and in Rus' alike the state grew from within. The final point was made in 2018 by the philologist Wojciech Banasik: "Dagome" turned out to be the Slavic name Drogomir, distorted by German spelling and a copyist's error. It was one and the same operation, carried out against one people twice, from two ends and in two different centuries.
A chronicle, not a sermon
The main part of the book is built as a chronicle, year by year, from a 5th-century dugout to the present war. The chapters are short, usually one event, one document or one person per chapter: Krewo, Grunwald, Horodło, Lublin, Brest, Hadiach, Poltava, the Partitions, the war for Lviv, the Peace of Riga, the Holodomor, Katyn, Volhynia, Operation Vistula, the Paris Kultura, Solidarity, the Orange Revolution, the Revolution of Dignity and February 2022.
One question runs through the whole chronicle, and I call it the "third chair": would Rus' become an equal third partner in the Polish-Lithuanian union, or remain its prey? In the book I single out 4 moments when the answer was almost yes.
The first is 1432. After the death of Vytautas, the Rus' lands of the Grand Duchy of Lithuania, from Polatsk and Smolensk to Kyiv and Volhynia, put Švitrigaila on the throne, and the chronicle recorded the appearance of a Grand Duchy of Rus' with its own ruler, army and council. The project lost the war, but it forced Kraków and Vilnius to return to the Orthodox nobility the rights that the Union of Horodło had taken away.
The second is the Treaty of Hadiach of September 16, 1658, which takes up more space in the book than any other episode. Its main author, Yurii Nemyrych, educated at Leiden, Basel, Paris and Oxford, proposed creating out of the Kyiv, Bratslav and Chernihiv voivodeships a Grand Duchy of Rus' as a third equal member of the Commonwealth. The duchy would have had its own hetman, ministers, court, treasury and coinage, 5 Orthodox seats in the Senate, a second academy and freedom of the press. The Sejm ratified the treaty in May 1659. I explain its collapse through 4 concrete causes. The treaty came 10 years of war too late: for the hundreds of thousands who had passed through Pyliavtsi, Berestechko and Batih, the word "Liakh" already meant an enemy. It was an agreement of the elite that promised nothing to the Cossack rank and file. The text ratified in Warsaw had been cut compared with the one signed at Hadiach. And Moscow worked against it, with an army and with letters to the Sich saying the hetman had sold the people to the Poles. The victory at Konotop saved nothing. Nemyrych was killed by insurgents, and Vyhovsky was later shot in Poland without trial.
The third is the Constitution of May 3, 1791, which reformed the Commonwealth but found no place in it for Rus'. Within 4 years the state was gone. The fourth is 1918-1920, when two young states fought each other for Lviv instead of forming an alliance, and the Peace of Riga sealed that outcome.
From this sequence I draw the main conclusion of the book. Every time Poles and Ukrainians chose to live apart, a third party won: Muscovy, then the Russian Empire, then the Soviet Union. This is not a conspiracy theory in which Moscow directs every event. The chapter on Volhynia states plainly that Moscow did not organise the slaughter. But the result of the slaughter worked for Moscow: it destroyed the possibility of a common Polish-Ukrainian front against the returning Red Army and handed Soviet propaganda an image it would use for half a century.
The difficult chapters
The real test of any book on this subject is Volhynia. I describe both sides in the same voice and do not invent symmetry where there was none. The killing in 1943 began from one side: on February 9 the UPA attacked the Polish colony of Parośla, and on July 11-12 it attacked about 100 Polish villages at once. Polish civilian victims number between 70,000 and 100,000, Ukrainian civilian victims of Polish formations between 10,000 and 15,000. But the same chapter also describes the Polish reprisals, including Sahryń on March 10, 1944, where at least 600 Ukrainian civilians were killed, the Polish police battalions in German punitive operations, and the thousands of Ukrainians who hid their Polish neighbours at the risk of their lives, threatened by the OUN's own security service. The Polish Sejm called Volhynia a genocide, the Ukrainian side speaks of a mutual tragedy, and many historians of both countries have settled on the formula of an ethnic cleansing with genocidal episodes, begun by the Ukrainian underground and answered by the Polish one.
Just as important is the chapter on Jerzy Giedroyc's Paris Kultura. It was there, in an émigré journal of the 1950s, that Poles first publicly gave up their claims to Lviv and Vilnius. It began with a letter from the priest Józef Majewski in 1952 and later grew into a doctrine associated with Juliusz Mieroszewski. The knot tied at Lublin began to come undone not at a congress or on a battlefield, but in a journal's editorial office.
How the book ends
The book ends not with an armistice but with an excavation. In April 2025, in the village of Puzhnyky in the Ternopil region, Polish and Ukrainian archaeologists together began the first exhumation of Polish victims after a 7-year moratorium. The book also begins with an excavation, a 5th-century Slavic dugout where a Pole and a Ukrainian cannot yet be told apart. Between these two excavations lie 15 centuries, 4 unions, 10 wars against each other and 3 fought side by side.
The conclusion from these 15 centuries is simple: we have far more in common than it seems, yet we always find reasons, if not to live apart, then to hate each other.
Res Unita. Poland and Ukraine: Fifteen Centuries of One History is available on Amazon.