page_title: Hessian War
section_title: Cause and opening phase
hierarchical_section_title: Hessian War / Course of the war / Cause and opening phase
caption_attribution_description: Français&#160;: Portrait de Philippe Ier de Hesse, anonyme, XVIe siècle.
context_page_description: The Hessian War, in its wider sense sometimes also called the Hessian Wars, was a drawn out conflict that took place between 1567 and 1648, sometimes pursued through diplomatic means, sometimes by military force, between branches of the princely House of Hesse, particularly between the Landgraviate of Hesse-Cassel and the Landgraviate of Hesse-Darmstadt. It was triggered by a division of inheritance following the death of the last landgrave of all Hesse, Philip I in 1567.
  The real conflict, which lasted almost 80 years and spanned three generations, escalated in the 1620s, when the line of Hesse-Marburg died out, and peaked after 1645 in the Hessian War proper. This open warfare began with the Siege of Marburg in 1645 and ended in April 1648 with victory going to Hesse-Cassel. In the aftermath, Upper Hesse was divided and parts of its territory went to the now stronger Hesse-Cassel.
  At a European level the Hessian War must be viewed in the larger context of the Thirty Years' War, in which the reformed Hesse-Cassel sided with the Protestant Swedish party, whilst Hesse-Darmstadt, despite its Lutheran confession joined the Catholic-Imperial alliance.
context_section_description: The cause of the conflict was the division of inheritance following the death of Phillip the Magnanimous in 1567. According to an old house law in the House of Hesse, he had mandated in his will a division of the landgraviate amongst his four sons, whereby the inheritance of Hessian territory was as follows: 
  His eldest son, William, was given the Lower Principality in the north of Hesse (subsequently referred to as  Hesse-Cassel) with the city of Kassel, in all about half of the territory of Hesse.
  His second son, Louis, was given Upper Hesse in the centre of Hesse (subsequently referred to as Hesse-Marburg) with the town of  Marburg and the fortress of Giessen, about a quarter of Hesse itself.
  His third son, Philip (the Younger), was given the Lower County of Katzenelnbogen in the west of Hesse (subsequently referred to as Hesse-Rheinfels) with Rheinfels Castle and Katzenelnbogen, roughly just over one eight of the territory of Hesse.
  His youngest son, George, was given the Upper County of Katzenelnbogen in the south of Hesse (subsequently referred to as Hesse-Darmstadt) with the town of Darmstadt, rather less than an eight of Hesse.
  When the Rheinfels line died out in 1583 Hessen-Rheinfels was divided amongst the three remaining brothers of Philip II.
caption: Philip I, the last landgrave of all Hesse (died 1567)
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