The Mongol Cataclysm and the Void in the Heart of Kyivan Rus

To understand the complex relationship between Ukraine and Russia, one must first appreciate the profound historical divergence that shaped their distinct trajectories. The year 1240 marked a watershed moment when Mongol forces under Batu Khan sacked Kyiv, devastating the capital of Kyivan Rus. This event triggered a massive political and demographic shift that would redefine Eastern Europe for centuries. By 1299, the metropolitan of Kyiv had relocated northeast to Vladimir and eventually to Moscow, leaving Ukraine’s central lands without strong leadership or spiritual guidance.

The Mongol Empire’s grip on the region proved inconsistent due to internal power struggles, creating a power vacuum across Ukraine’s territories. This absence of centralized authority allowed new forces to emerge and reshape the political landscape. The former principalities of Kyivan Rus now existed in a state of fragmentation, with local rulers exercising limited autonomy under nominal Mongol suzerainty. This period of disruption laid the groundwork for four centuries of separation from the northeastern principalities that would eventually coalesce into Muscovite Russia.

Lithuanian Expansion: A New Political Order Emerges

As the 14th dawned, the Baltic principality of Lithuania began its remarkable expansion eastward. Having secured their western frontiers against Germanic crusaders, the Lithuanians turned their attention to the vulnerable lands of former Kyivan Rus. Under Grand Duke Algirdas, who famously declared “all Rus must belong to Lithuanians,” they captured territories in modern-day Belarus during the 1340s and pushed into Ukrainian lands.

The Lithuanian advance was not solely military conquest. In 1362, they captured Kyiv largely through diplomatic maneuvering rather than siege warfare. The following year, their victory over the Mongols at the Battle of Blue Waters secured control over the Dnipro River basin. By century’s end, Lithuania had become Europe’s largest political entity, stretching from the Baltic to the Black Sea.

Lithuanian rule proved remarkably accommodating to local traditions. Unlike the Mongols, they imposed minimal tribute demands and granted local Slavic nobility participation in governance. Many Ukrainian elites welcomed Lithuanian overlordship as preferable to Mongol domination. The state officially styled itself as the Grand Duchy of Lithuania, Rus, and Samogitia, with rulers bearing the title “Grand Duke of Lithuania and Ruthenia.” Ruthenian, the ancestor of modern Ukrainian and Belarusian, became the chancery language, and Kyivan Rus legal codes remained in force. This cultural flexibility led some Ukrainian historians to view the Lithuanian-Ruthenian state as a recreation of Kyivan Rus rather than foreign domination.

Polish Expansion and the Union of Krewo

While Lithuania expanded into central Ukraine, Poland simultaneously moved to capture the Kingdom of Galicia-Volhynia, the strongest successor state to Kyivan Rus after the Mongol invasion. King Casimir the Great of Poland launched his campaign in 1340, though he faced resistance from local nobles and Lithuanian rivals. By 1366, he had secured most of Galicia and part of Volhynia, establishing a temporary modus vivendi with Lithuania.

The political landscape transformed dramatically in 1385 with the Union of Krewo. This personal union brought together Poland and Lithuania through the marriage of 11-year-old Queen Jadwiga of Poland to Grand Duke Jogaila of Lithuania, who converted to Catholicism and took the name Władysław II Jagiełło. The agreement promised to incorporate Lithuanian and Ruthenian territories into Poland “in perpetuum,” though Lithuania retained considerable autonomy.

Polish rule introduced different challenges for Ukrainians. Unlike the religiously flexible Lithuanians, Polish authorities promoted Catholicization aggressively. Nobility privileges were reserved for those who converted to Catholicism, Latin replaced Ruthenian as the official language in Galicia, and Catholic nobles received estates in exchange for loyalty to the Polish crown. These policies created religious and cultural tensions that would shape Ukrainian-Polish relations for centuries.

The Polish-Lithuanian Commonwealth: A Noblemen’s Paradise

By the 16th century, Lithuania’s power had waned significantly against rising Muscovite strength. After losing the northeastern Ukrainian cities of Chernihiv and Starodub to Moscow in 1522, and facing further threats during the Livonian War (1558-1583), Lithuania turned to Poland for support. The resulting Union of Lublin in 1569 created the Polish-Lithuanian Commonwealth, a single political entity with an elected monarch, shared parliament (Sejm), common currency, and unified foreign policy.

The Commonwealth represented a remarkable political experiment for its time. With a constitutional monarchy, limited royal power, and approximately 10% of the population enjoying political rights through the noble class (szlachta), it was among Europe’s most progressive political systems. Yet this “nobles’ democracy” increasingly became what historian Norman Davies called “a noblemen’s paradise” where magnates held disproportionate power.

For Ukrainians, Commonwealth rule brought mixed consequences. The feudal system intensified, with peasants losing their freedom of movement in 1505 and becoming serfs “in exceptionally miserable conditions,” as one contemporary observed. Urban centers declined as nobles restricted merchants’ rights. Ruthenian nobility faced intense pressure to Polonize and convert to Catholicism, with non-Catholics barred from political office and Orthodox educational institutions closed.

Religious Transformation and the Union of Brest

Facing the impracticality of converting all Orthodox Ruthenians to Catholicism, Polish authorities devised a compromise: the Union of Brest in 1596 created the Greek Catholic Church, which maintained Orthodox liturgy while acknowledging papal authority. Some Orthodox hierarchs supported this move hoping to gain political influence, but many clergy and believers saw it as betrayal.

The religious controversy sparked resistance across Ukraine. Orthodox brotherhoods organized educational and publishing initiatives to preserve their traditions. This religious struggle culminated in the leadership of Petro Mohyla, who became Metropolitan of Kyiv in 1632 and initiated sweeping reforms. He standardized Orthodox liturgy, reformed the clergy, established the Mohyla Collegium (the first institution of higher education in the East Slavic world), and strengthened Latin studies. Despite accusations of Latinization, Mohyla is remembered as a reviver of Ruthenian tradition who helped create a distinct religious identity for Ukrainians.

The Cossack Phenomenon: Frontiersmen of the Wild Field

In the southern borderlands between the Commonwealth, Russia, and the Crimean Khanate, a new social group emerged: the Cossacks. Derived from the Turkic word qazaq (free man), they consisted of runaway serfs, religious refugees, disaffected nobles, and adventurers living beyond state control. First mentioned in historical records in 1492, they established their fortified settlements called siches, with the main Zaporizhian Sich emerging in the 1550s on islands beyond the Dnipro rapids.

The Cossacks developed a unique military democracy. Their assembly (rada) elected leaders called hetmans, and their ranks were open to all Christian men (though women were prohibited). While romanticized in Ukrainian folklore as freedom-loving democrats, contemporaries also noted their violence and drinking culture. A Venetian envoy remarked that had the Cossacks “been as sober as the Spartans, their republic would have resembled Sparta.”

Militarily, the Cossacks became a significant force. They fought alongside Polish armies against Moscow and the Ottomans, even raiding Constantinople’s suburbs in 1615 and 1620. At the Battle of Khotyn in 1621, they saved a Polish army from certain defeat by the Ottomans. Yet they remained difficult subjects for the Commonwealth, rebelling in 1591, 1594-1596, 1625, 1635, and 1637 over issues including religious rights, political recognition, land disputes, and broken promises.

The Great Revolt of Bohdan Khmelnytsky

The largest Cossack uprising began in 1648 under Hetman Bohdan Khmelnytsky, a registered Cossack and minor nobleman whose estate had been plundered by a Polish magnate, with his son killed and his fiancée kidnapped. After failing to obtain justice through legal channels, he fled to the Sich and was elected hetman.

Khmelnytsky’s rebellion initially achieved spectacular success. With support from the Crimean Tatars (traditional enemies who became temporary allies), the Cossacks won decisive victories at Yellow Waters and Korsun in 1648. The uprising sparked widespread peasant revolts against Polish landowners and Jews, who were often seen as agents of the oppressive economic system. Orthodox clergy declared the rebellion a holy war, with Metropolitan Sylvestr Kosiv hailing Khmelnytsky as a “new Moses.”

By 1649, Khmelnytsky controlled most of central Ukraine, establishing the Cossack Hetmanate with its capital in Kyiv. His ultimate goals remain debated—whether he sought full independence, autonomy within the Commonwealth, or simply redress of grievances. Internal divisions emerged over issues like serfdom (which Khmelnytsky, himself a landowner, tended to preserve), and the alliance with the Tatars proved unstable as they continued taking Ukrainian slaves despite the partnership.

The Fateful Decision: The Pereiaslav Agreement

After military fortunes shifted against him, particularly following the betrayal by his Tatar allies at the Battle of Berestechko in 1651, Khmelnytsky sought new external support. He turned to Moscow, which had its own interests in weakening Poland and protecting Orthodox believers.

In January 1654, at Pereiaslav, Khmelnytsky accepted the tsar’s protection over Ukraine. The exact nature of the agreement remains contested. Khmelnytsky likely expected a military alliance that would preserve Cossack autonomy, but Moscow interpreted it as submission to tsarist authority. The Treaty of Pereiaslav dramatically transformed the regional balance of power, making Russia the dominant force in Eastern Europe and linking most of Ukraine with Russia for the next three centuries.

The aftermath brought further conflict rather than stability. Russia invaded Poland, Sweden entered the war against both, and Transylvania joined the attempted partition of the Commonwealth. When Russia separately made peace with Poland in 1656 without consulting the Cossacks, it strained the Moscow-Hetmanate relationship. Khmelnytsky died in 1657 amid this chaos, leaving a contested legacy.

The Aftermath: Partition and the “Ruin”

The period following Khmelnytsky’s death became known as “The Ruin” as Ukraine descended into decades of civil war and foreign intervention. His successor, Hetman Ivan Vyhovskyy, attempted to reorient toward Poland through the Union of Hadiach in 1658, which would have created a Ruthenian principality as an equal member of the Commonwealth with unprecedented autonomy. However, Russian military intervention prevented implementation of this agreement.

The subsequent Treaty of Andrusovo in 1667 formally partitioned Ukraine along the Dnipro River, with left-bank territories going to Russia and right-bank lands remaining with Poland (though Russia retained Kyiv despite treaty provisions). The “Eternal Peace” of 1686 confirmed this division and granted Russia the right to intervene in Commonwealth affairs to protect Orthodox believers—a humiliating clause for Poland.

Competing Legacies and Modern Relevance

Khmelnytsky’s legacy remains deeply contested. Soviet historiography emphasized class struggle over national liberation, portraying the uprising as a peasant revolt against feudal oppression. Ukrainian national narratives often celebrate him as a hero fighting for independence, though this overlooks the complexities of his goals and the tragic consequences of his alliance with Moscow.

The nineteenth-century Ukrainian poet Taras Shevchenko captured the ambiguous legacy succinctly: “You boasted that we once/Brought ruin upon Poland./True: Poland fell,/But you were crushed as well.” The statue of Khmelnytsky erected in Kyiv in 1888 symbolizes these competing interpretations—his mace points toward Moscow, commemorating the “reunification” of Ukrainian and Russian peoples in Russian narratives, while the original design would have shown him trampling a Polish noble, Catholic priest, and Jew, reflecting the uprising’s violent ethnic and religious dimensions.

For contemporary Ukraine, this four-century period of separation from Moscow represents a crucial historical experience that shaped distinct political traditions, religious affiliations, and cultural developments. The memory of the Hetmanate remains a potent symbol of Ukrainian statehood, while the partitions and subsequent incorporation into the Russian Empire continue to influence modern geopolitical orientations. Understanding this complex history is essential for comprehending the ongoing relationship between Ukraine and Russia, and the enduring Ukrainian aspiration for self-determination that continues to shape European politics today.