Charles X Gustav
Charles X Gustav, also Carl X Gustav, was King of Sweden from 1654 until his death in 1660. He was the son of John Casimir, Count Palatine of Zweibrücken-Kleeburg, and Catherine of Sweden. After his father's death, he also succeeded him as Pfalzgraf. He was married to Hedwig Eleonora of Holstein-Gottorp, who bore his son and successor, Charles XI. Charles X Gustav was the second Wittelsbach king of Sweden after the childless king Christopher of Bavaria and he was the first king of the Swedish Caroline era, which had its peak during the end of the reign of his son, Charles XI. He led Sweden during the Second Northern War, enlarging the Swedish Empire. By his predecessor Christina, he was considered de facto Duke of Eyland, before ascending to the Swedish throne. From 1655 to 1657, he also claimed the title of Grand Duke of Lithuania.
His numbering as Charles X derives from a 16th-century invention. One of his predecessors, Charles IX, chose his numeral after studying a fictitious history of Sweden. Charles X Gustav was the fourth actual King Charles, but has never been called Charles IV.
Heir presumptive
Charles Gustav's mother and father had fled the Thirty Years' War and never went back to Germany. In his early childhood, raised in the Swedish court alongside his cousin Queen Christina, he received an excellent civil education. Later Charles X learned the art of war under Lennart Torstenson, being present at the second Battle of Breitenfeld and at Jankowitz. From 1646 to 1648 he frequented the Swedish court, supposedly as a prospective husband of his cousin, the queen regnant, Christina of Sweden, but her insurmountable objection to wedlock put an end to these anticipations, and to compensate her cousin for a broken half-promise she declared him her successor in 1649, despite the opposition of the Privy Council headed by Axel Oxenstierna. In 1648 he gained the appointment of commander of the Swedish forces in Germany. The conclusion of the treaties of Westphalia in October 1648 prevented him from winning the military laurels he is said to have desired, but as the Swedish plenipotentiary at the executive congress of Nuremberg, he had an opportunity to learn diplomacy, a science he is described as having quickly mastered. As the recognized heir to the throne, his position on his return to Sweden was dangerous because of the growing discontent with the queen. He therefore withdrew to the isle of Öland until the abdication of Christina on 5 June 1654 called him to the throne.Early days as king
Charles X Gustav was crowned on 7 June 1654, the day after his cousin Christina abdicated. The beginning of Charles X's reign concentrated on the healing of domestic discords and on the rallying of all the forces of the nation round his standard for a new policy of conquest. On the recommendation of his predecessor, he contracted a political marriage on 24 October 1654 with Hedwig Eleonora, the daughter of Frederick III, Duke of Holstein-Gottorp. He was hoping to secure a future ally against Denmark. The Riksdag that assembled at Stockholm in March 1655 duly considered the two great pressing national questions: war, and the restitution of the alienated crown lands. Over three days a secret committee presided over by the King decided the war question: Charles X easily persuaded the delegates that a war against Poland appeared necessary and might prove very advantageous; but the consideration of the question of the subsidies due to the crown for military purposes was postponed to the following Riksdag. In 1659 he proclaimed severe punishment for anyone hunting in the royal game reserve in Ottenby, Öland, Sweden, where he had built a long dry-stone wall separating the southern tip of the island.Second Northern War (1655–1660)
War in Poland-Lithuania
On 10 July 1655, Charles X left Sweden to engage in a war against the Polish–Lithuanian Commonwealth, in what became the Second Northern War. By the time war was declared he had at his disposal 50,000 men and 50 warships. Hostilities had already begun with the occupation of Dünaburg in Polish Livonia by the Swedes on 1 July 1655. Then on 21 July 1655 Swedish army under Arvid Wittenberg crossed into Poland and proceeded towards the encampment of the Greater Poland Levy of the Nobility encamped among the banks of the Noteć river, with some regular infantry for support. On 25 July the Polish noble levy army capitulated, and the voivodeships of Poznań and Kalisz placed themselves under the protection of the Swedish King. Thereupon the Swedes entered Warsaw without opposition and occupied the whole of Greater Poland. The Polish king, John II Casimir of Poland of the House of Vasa, eventually fled to Silesia after his armies had suffered defeats. A great number of Polish nobles and their personal armies joined the Swedes, including the majority of the famous Winged Hussars. Many Poles saw Charles X Gustav as a strong monarch who could be a more effective leader than John II Casimir.Meanwhile, Charles X Gustav pressed on towards Kraków, which the Swedes captured after a two-month siege. The fall of Kraków followed a capitulation of the Polish Royal armies, but before the end of the year a reaction began in Poland herself. On 18 November 1655 the Swedes invested the fortress-monastery of Częstochowa, but the Poles defended it and after a seventy days' siege the Swedish besiegers had to retire with great loss. This success elicited popular enthusiasm in Poland and gave rise to a nationalistic and religious rhetoric concerning the war and Charles X. He was depicted as tactless and his mercenaries barbaric. His refusal to legalize his position by summoning the Polish diet and his negotiations for the partition of the very state he affected to befriend awoke a nationalistic spirit in the country.
File:Anonymous Triumph of Charles X Gustavus.jpg|thumb|Triumph of Charles X Gustav over the Polish–Lithuanian Commonwealth, National Museum in Warsaw
In the beginning of 1656 King John II Casimir returned from exile, and the reorganised Polish army increased in numbers. By this time Charles had discovered that he could more readily defeat the Poles than conquer Poland. What is described as his chief object, the conquest of Prussia, remained unaccomplished, and a new Swedish adversary arose in the elector of Brandenburg, Frederick William I, alarmed by the ambition of the Swedish king. Charles forced the elector, albeit at the point of the sword, to become his ally and vassal ; but the Polish national rising now imperatively demanded his presence in the south. For weeks he engaged in the pursuit of Polish divisions engaged in guerrilla tactics in the snow-covered plains of Poland, penetrating as far south as Jarosław in Ruthenian Voivodeship, by which time he had lost two-thirds of his 15,000 men army with no apparent result. In the meantime, the Russians signed a cease-fire with the Polish–Lithuanian Commonwealth and then pursued a campaign in Livonia and laid siege to Riga, the second largest city in the Swedish Realm.
Charles's retreat from Jarosław to Warsaw almost ended with disaster. His forces were trapped by the three converging Polish-Lithuanian armies in a marshy forest region intersected in every direction by well-guarded rivers. Escaping this disaster is considered one of his most brilliant achievements. But on 21 June 1656 the Poles retook Warsaw, and four days later Charles was obliged to purchase the assistance of Frederick William I, by the treaty of Marienburg. On 28–30 July the combined Swedes and Brandenburgers, 18,000 strong, after a three days' battle, defeated John Casimir's army of 40,000 at Warsaw, however the Polish-Lithuanian forces promptly withdrew with no large losses and apparent strong will to fight another day, while Swedish host reoccupied the Polish capital again, causing much destruction to the city and its inhabitants. However, this feat of arms did not have the desired result for Charles, and when Frederick William compelled the Swedish king to open negotiations with the Poles, they refused the terms offered, the war resumed, and Charles concluded an offensive and defensive alliance with the elector of Brandenburg which stipulated that Frederick William and his heirs should henceforth possess the full sovereignty of East Prussia.