The Siege of Memel was the first major Russian military success during the Seven Years' War and the opening operation of the Russian campaign in East Prussia. As part of Russia's strategy to weaken Frederick II and fulfill its alliance obligations with Austria, the operation aimed to secure an important Baltic port that could serve as a supply base for Russian operations. In June 1757, a Russian corps commanded by General William Fermor, supported by a squadron of the Russian Baltic Fleet, besieged the Prussian fortress of Memel (modern-day Klaipėda). Defended by a small garrison under Lieutenant Colonel Christoph Ernst von Rummel, the fortress surrendered after a brief siege, becoming the first Prussian fortress captured by Russia during the war. The occupation of Memel provided the Russian Imperial Army with a strategic logistical base for further operations in East Prussia and marked the beginning of Russia's direct military campaign against Prussia.
The Diplomatic Background
Following the Treaty of Nystad in 1721, the Russian Empire emerged as a major European power, particularly in the Baltic Sea region. The decline of Swedish influence allowed Russia, under Peter I and his successors, to expand its diplomatic and military influence in Northern Europe. At the same time, Russia's rivalry with the Ottoman Empire encouraged closer relations with the Habsburg monarchy, which shared Russian concerns regarding Ottoman influence in the Balkans and the balance of power in Central Europe.
These common interests led to the Treaty of Vienna of 1726, which established a formal alliance between Russia and Austria. Despite the political instability following the deaths of Peter I and Catherine I, including the reigns of Peter II, Anna, Ivan VI, and Elizabeth, cooperation between the two empires remained one of the foundations of European diplomacy during the first half of the eighteenth century.
The alliance was strengthened through Russian participation in the War of the Polish Succession and the War of the Austrian Succession, during which Russia supported Maria Theresa. It was formally renewed by the Treaty of Saint Petersburg of 1746, which required each state to provide up to 30,000 troops—20,000 infantry and 10,000 cavalry—within three months if the other was attacked, while also reaffirming broader military and logistical cooperation. This renewed cooperation alarmed Frederick II of Prussia, who viewed the Austro-Russian alliance as a potential threat to Prussian expansion and influence in Central Europe.
Russian concerns regarding Prussia increased after Frederick II's seizure of Silesia and the rapid growth of Prussian military power. Russian statesmen, particularly Chancellor Alexey Bestuzhev-Ryumin, increasingly considered Prussia the principal obstacle to Russian security and to the European balance of power established after the previous wars.
These concerns shaped Russian military policy in 1756. On 15 March of that year, the Imperial Conference approved a strategy directed against Prussia, which was endorsed by Empress Elizabeth. The plan aimed to prevent further Prussian expansion and reduce Frederick II's power to a level that would no longer threaten Russian interests. It called for military coordination with Austria, preparations of the Russian Imperial Army, diplomatic efforts to secure the movement of Russian forces through the Polish–Lithuanian Commonwealth, the preservation of Swedish and Ottoman neutrality, and cooperation with France to prevent interference with the coalition's plans.
The Diplomatic Revolution of 1756 transformed the European alliance system by bringing Austria and France together, but it did not alter Russia's determination to oppose Prussia. Saint Petersburg remained committed to its alliance with Vienna and joined the anti-Prussian coalition despite British and Prussian diplomatic attempts to prevent such cooperation.
Frederick II's pre-emptive invasion of the Electorate of Saxony in August 1756 transformed the diplomatic crisis into the Third Silesian War and accelerated Russian preparations for intervention. During the winter of 1756–1757, the Russian government converted its diplomatic commitments into operational planning and concentrated forces for an invasion of East Prussia. Within this framework, the fortress and port of Memel was selected as the opening objective of the Russian campaign, both to secure a Baltic supply base and to support the subsequent advance into East Prussia.
Contemporary Prussian publications presented a different interpretation of the origins of the conflict. The alliance between Austria and Russia was portrayed as a defensive arrangement that had existed for years without justification for war, while Frederick II was presented as the victim of an aggressive coalition formed by the European powers.
Russian Preparations
Following the decisions of the Imperial Conference in March 1756, Russian foreign and military policy became increasingly focused on limiting the power and expansion of Prussia. The strategic program approved by the Conference established the foundations of Russia's future intervention by calling for close military coordination with the Habsburg Monarchy, diplomatic measures to prevent foreign interference, negotiations with the Polish–Lithuanian Commonwealth to secure the movement of Russian forces, and preparations for offensive operations by the Russian Imperial Army against Frederick II.
Although Russia possessed one of the largest standing armies in Europe at the beginning of the Seven Years' War, its military preparations were affected by significant organizational difficulties. According to the establishment returns compiled by the War College in 1755, the Russian military consisted of approximately 331,000 men, including the field army, garrison troops, artillery and engineer formations, land M=militia, and irregular cavalry. For offensive operations, Russia could theoretically deploy around 220,000 field and irregular troops; however, the forces actually available for the 1757 campaign were considerably lower due to shortages, detachments, and incomplete formations.
Prussian observers also recognized the considerable scale of the Russian military effort assembled for the invasion of East Prussia. The Russian army operating under Field Marshal Stepan Fyodorovich Apraksin included regular infantry and cavalry formations as well as large numbers of irregular troops, supported by several hundred artillery pieces. Contemporary assessments emphasized the quality of the Russian grenadiers, who were regarded as the core of the army, alongside the discipline and training of the musketeer regiments.
The army assigned to Field Marshal Apraksin's command was particularly affected by recent reforms. The creation of new Grenadier regiments and the formation of Shuvalov's Observation Corps required the redistribution of experienced soldiers and officers from existing infantry formations, weakening several regiments intended for field operations. According to Dmitry Maslovsky, Apraksin's army began the campaign approximately 9,000 men below its authorized strength, with shortages reaching around 12,000 when non-combatants were included.
Despite these administrative and organizational problems, Maslovsky argued that the Russian army under Empress Elizabeth was considerably more effective than contemporary critics had suggested. The officer and non-commissioned officer corps possessed extensive military experience, while the long period of service and the recruitment system contributed to the endurance and discipline of the infantry. Although logistical and administrative weaknesses remained significant challenges, the regular infantry represented one of the strongest elements of the Russian military system at the beginning of the Seven Years' War.
Following the Prussian invasion of Saxony in August 1756, the Russian government transformed its political commitments into concrete military planning. On 5 October 1756, the Imperial Conference issued detailed instructions to Field Marshal Stepan Fyodorovich Apraksin, defining both the strategic objectives and practical requirements of the forthcoming campaign. Russia justified its intervention through its alliance obligations with Austria and Saxony, but also through its own interest in preventing further Prussian expansion. Since Russian forces could not immediately cooperate with the Austrian army in the main theatre of war, Apraksin was ordered to conduct an independent offensive into East Prussia in order to divert Prussian forces away from Central Europe.
The instructions issued to Apraksin established the operational foundations of the Russian campaign. Troops were to be concentrated in Livonia and Courland, supply depots established, siege artillery and transport prepared, intelligence gathered on Prussian positions and communications, and cooperation between the army and the Russian Baltic Fleet organized for future operations along the Baltic coast. Following the capitulation of Memel, the Russian command incorporated the fortress into the logistical framework of the East Prussian campaign. The port was particularly valuable because Russian planners had already designated Memel as one of the magazines to be supplied from Saint Petersburg by the transport fleet. From Libau, supplies for Fermor's detachment were transported toward Memel by inland waterways and by wagon columns, allowing the Russian force operating against the fortress to maintain its advance.
The objectives of the campaign were further clarified during the Russian Military Council of 17 February 1757. The commanders concluded that the purpose of the invasion was not merely the occupation of Königsberg, but the destruction of the Prussian field army in East Prussia. The council emphasized that the direction of the advance and the crossing points over the Neman River should remain flexible and dependent on the position of Prussian forces rather than being determined solely by theoretical plans.Korobkov, Семилетняя война, pp. 113–114.
Mobilization of the Russian Army During the second half of 1756, the Russian government transformed the strategic decisions adopted earlier in the year into practical military preparations. The campaign against Prussia required not only the concentration of a large field army, but also the organization of supply systems, transport, naval cooperation and intelligence networks necessary for an offensive operation beyond Russia's western frontier.
At the beginning of the Seven Years' War, the Russian Empire possessed one of the largest military establishments in Europe. According to the official returns compiled by the War College in 1755, the Russian armed forces consisted of approximately 331,422 men, including field troops, garrison forces, artillery and engineer formations, the land militia, and irregular cavalry units. However, only a portion of this establishment could be employed in offensive operations. The field army consisted of approximately 176,073 regular troops, supported by around 43,733 irregular troops, providing Russia with roughly 220,000 men theoretically available for active service.
The infantry formations intended for active operations had already undergone major organizational changes before the beginning of the campaign. Before the war, the Russian infantry consisted of three Guards regiments and forty-six army infantry regiments. On 30 March 1756 (O.S.), thirty-two regiments were placed on a full war establishment, allowing them to undertake field operations, while the remaining formations were retained for internal security duties and reserve purposes.