With the death of the childless Landgrave Henry Raspe in 1247, the Ludowingian line of Thuringian landgraves becomes extinct in the male line.

His property includes only large parts of Thuringia; also, the Countship of Hesse had come into Ludowingian possession through the female line.

In 1122, before his acquisition of the title of Landgrave, Count Louis I of Thuringia had married Hedwig of Gudensberg, the female heir of the Hessian countly family of the Gisonen.

The Gisonen, whose lands were initially mainly in the upper Lahn area, had previously come into the significant inheritance of Count Werner in Lower Hesse.

Then, through the marriage of Giso IV with Kunigunde of Bilstein, they had also acquired widespread property and vogtship rights from the Counts of Bilstein.

Claims on the Ludowingians' inheritance are made by Henry Raspe's niece and his nephew.

Sophie of Thuringia, married to Henry II, Duke of Brabant and Lothier, is the daughter of Henry Raspe's brother Louis IV and she claims the territories on behalf of her son Henry.

(Sophie's sister Gertrude is abbess of the imperial convent of Altenberg in Wetzlar and thus excluded from the succession.)

Henry III, Margrave of Meissen, is the son of Henry Raspe's sister Jutta.

Another competitor is the Archbishop of Mainz, who can claim Hesse is a fiefdom of the Archbishopric and now, after the extinction of the Ludowingians, demands its return.

The war will last seventeen years.

The war between Pomerania and the Teutonic Knights is renewed in 1247 when large Teutonic reinforcements arrive in Prussia.

On Christmas Eve of 1247, the Knights besieged and overwhelm a major Pogesanian fortress, which they later rename Christburg (Dzierzgoń), and newly arrived Henry III, Margrave of Meissen, subdues the Pogesanians.

Swietopolk retaliates and destroys Christburg, but the Knights rebuild it in a new location.

Both the Prussian and Pomeranian armies fail to capture the new castle.

Otto III of Brandenburg raids Warmia and Natangia, forcing the locals to surrender.

The peace talks that began in 1247 had achieved little, but a new truce had been arranged in September 1248 and peace is made on November 24, 1248.

Swietopolk has to return lands seized from his brothers, allow Teutonic Knights to pass through his domains, stop charging tolls on ships using the Vistula, and stop any aid to the Prussians.

The Prussians are compelled to sign the Treaty of Christburg on February 7, 1249.

The treaty provides personal freedom and rights to newly converted Christians.

The peace of February has formally ended the Prussian uprising, but Marshal Heinrich Botel gathers men from Kulm, Elbing, and Balga for an expeditionary attack deeper into Prussia in autumn 1249.

They travel into the lands of Natangians and pillage the region.

On their way back, they are in turn attacked by an army of Natangians.

The Knights retreat to the nearby village of Krücken south of Kreuzburg (now Kamenka south of Slavskoye), where Prussians hesitate to attack, but the Prussian army is growing as fresh troops arrive from more distant territories, and the Knights do not have enough supplies to withstand a siege.

Therefore, the Teutonic Knights bargain for surrender: the marshal and three other knights are to remain as hostages while the others are to lay down their weapons.

The Natangians break the agreement and massacre fifty-four knights and a number of their followers.

Some knights are executed in religious ceremonies or tortured to death.

The severed head of Johann, vice-komtur of Balga, is mockingly displayed on a spear.

Others are ransomed or exchanged, including Marshal Botel.

Such barbarity gives the Knights an excuse not to treat the Prussians as civilized and honorable people.

Never again will the Knights surrender to pagans.

The Natangians do not exploit their victory and do not make offensive moves into the lands of the Teutonic Knights.

It will take two years for the crusading military order to recover and avenge the massacre.

The skirmishes will last until 1253.

Thuringia, named after the Thuringian people who occupied it around 300, had come under Frankish domination in the sixth century, forming a part (from 1130 a landgravate) of the subsequent Holy Roman Empire.

The death of Landgrave Ludwig IV and consequent extinction of the reigning Ludowingian line of counts in 1247 had sparked the seventeen-year War of the Thuringian Succession, in which Ludwig’s daughter Sophia (1224-84), who had married Henry II, Duke of Brabant, wins the western half of the langravate for her son Henry I, called the Child.

At war’s end in 1264, this portion will become independent under the name of Hesse, never to become a part of Thuringia again.

Most of the remaining Thuringian lands will come under the rule of the Wettin dynasty of the nearby Margravate of Meißen, the nucleus of the later duchy and kingdom of Saxony.

The oldest record of Weimar, located on the Ilm River in Thuringia, dates from the year 899.

Ruled by the counts of Weimar-Orlamünde from 1247, it is declared a town in 1254.

(The future capital of the Duchy—after 1815 the Grand Duchy—of Saxe-Weimar, the city will also give its name to the Weimar Republic, the German state between the World Wars of the twentieth century).

Louis, in Donauwörth in 1256, orders the execution of his wife Marie of Brabant—a daughter of Henry II, Duke of Brabant and Marie of Hohenstaufen—due to mistaken suspicion of adultery, although any actual guilt on her part could never be validated.

As expiation, Louis founds a Cistercian friary, Fürstenfeld Abbey (Fürstenfeldbruck), near Munich.

Louis supports Richard of Cornwall during the German interregnum that follows King William's death in 1256.

Duchess Sophia of Brabant, after the War of the Thuringian Succession that had followed the death of her uncle Landgrave Henry Raspe in 1247,  had secured the Hessian possessions for her minor son Henry the Child, who had become the first Landgrave of Hesse and founder of the House of Hesse in 1246.

The remaining Thuringian landgraviate had fallen to the Wettin margrave Henry III of Meissen.

As a result of the war, Hesse gains its independence in 1264 and becomes a Landgraviate within the Holy Roman Empire.