The Landgraviate of Hesse-Kassel was founded by William IV the Wise, the eldest son of
Philip I. On his father's death in 1567, the
Landgraviate of Hesse was divided into four parts. William IV received about half of the territory, with
Kassel as his capital. Hesse-Kassel expanded in 1604 when
Maurice, Landgrave of Hesse-Kassel inherited the Landgraviate of Hesse-Marburg from his childless uncle,
Louis IV, Landgrave of Hesse-Marburg (1537–1604).
Thirty Years' War In 1605, Maurice became
Calvinist. When the
Thirty Years' War began, he was on the Protestant side. After being forced to cede some of his territories to
Hesse-Darmstadt, Maurice abdicated in 1627 in favour of his son
William V. His younger sons received
appanages, which created several
cadet lines in yet another
partition of Hesse. William V allied himself with
Gustavus Adolphus of Sweden and then
France, losing most of Hesse-Kassel when
Imperial troops invaded. He died in exile in 1637, leaving his widow
Amalie Elisabeth of Hanau-Münzenberg to act as regent for their eight-year-old son
William VI. Amalie Elisabeth vigorously advanced the interests of Hesse-Kassel. After expelling Imperial troops from Hesse-Kassel, she sent troops to take the city of
Marburg, which her father-in-law had lost to their Hesse-Darmstadt relatives. At the
Peace of Westphalia in 1648, Hesse-Kassel was further rewarded with most of the
County of Schaumburg and the newly secularized
Hersfeld Abbey. Amalie Elisabeth also introduced the rule of primogeniture to prevent Hesse-Kassel from being divided again in the future. However, her health was ruined by the stresses of the war, and she died in 1651. Hesse-Kassel was very heavily militarized for its population during the war (aided by French subsidies and funds obtained from looting), maintaining an average of about 10,000 soldiers in the field during the 1635-1648 phase (including 11,040 at the conclusion of the war in October 1648).
17th and 18th centuries William VI, who came of age in 1650, was an enlightened patron of learning and the arts. He was succeeded by his son
William VII, Landgrave of Hesse-Kassel, then an infant, who died in 1670. He was succeeded by his brother
Charles I. Charles' chief claim to fame is that he
hired out his soldiers to foreign powers as auxiliaries, as a means of improving the finances of his principality. William V was succeeded by Landgraves
William VI and
William VII.
Frederick I of Sweden, the next
landgrave, became by marriage
King of Sweden. Although the Landgraviate was in
personal union with Sweden from 1730 to 1751, the king's younger brother,
Prince William, ruled in Kassel as regent until he succeeded his brother as William VIII. On Frederick I's death in 1751, he was succeeded by his brother
William VIII, who fought as an ally of
Kingdom of Great Britain during the
Seven Years' War. His successor,
Frederick II, converted to
Catholicism after a long line of Protestant Landgraves. When the
American Revolutionary War broke out, Frederick II
leased Hessian troops to Great Britain for service in America.
End of the landgraviate Hesse fought on the side of Coalition in the
War of the First Coalition, against the First French Republic. In 1801, they would cede territories on the west bank of the Rhine to France. Following the reorganization of the German states during the
German mediatisation of 1803, the Landgraviate of Hesse-Kassel gained land and was raised to the
Electorate of Hesse and Landgrave William IX was elevated to
Imperial Elector, taking the title
William I, Elector of Hesse. The principality thus became known as ''
(aka Kurfürstentum Hessen''), although still usually referred to as Hesse-Kassel. In 1806, William I was dispossessed by
Napoleon Bonaparte for his support of the
Kingdom of Prussia in the
War of the Fourth Coalition. Kassel was designated as the capital of a new
Kingdom of Westphalia, where Napoleon appointed his brother
Jérôme Bonaparte as king. Following Napoleon's defeat in 1813, the elector was restored. At the
Congress of Vienna, a number of Napoleonic electorates were elevated to kingdoms, and William tried to secure recognition as King of the
Chatti. However, he was rebuffed by the Great Powers, who listed him as a "Royal Highness" along with the other grand dukes. To secure his pre-eminence over his cousin, the
Grand Duke of Hesse in the former Hesse-Darmstadt, William chose to keep his title of Prince-Elector. The rulers of the Electorate of Hesse became the only Prince-Electors in the
German Confederation, even though there was no longer a Holy Roman Emperor for them to elect. == Hessian troops in foreign service ==