Möngke has conducted a census of the…

Möngke, taking command personally late in the decade, has captured many of the Song’s fortified cities along the northern front.

These actions ultimately rendered the conquest a matter of time.

Having waged a series of brilliantly successful campaigns against the Song between 1257 and 1259, Möngke dies on August 11, 1259 near the site of the siege of Fishing Town in modern-day Chongqing.

The Khan’s sudden death halts the war and allows the Song time to revive.

There are several different accounts as to how he perished.

One was that he had been killed by an arrow shot from a Chinese archer during the siege.

Other accounts claim that he was killed by dysentery or even a cholera epidemic.

In any case, his death will ultimately force Hulagu to abort his campaign in Syria and Egypt, and cause another succession crisis, as Kublai and his brother Ariq Böke both claim the Mongol throne.

The ensuing civil war will destroy the unity and invincibility of the Mongol Empire.

The Mongols under Jalairtai Qorchi, in the final successful campaign against Korea, have launched four devastating invasions between 1253 and 1258 at tremendous cost to civilian lives throughout the Korean peninsula.

The Mongols annex the northern provinces of Korea after the invasions and incorporate them into their empire.

The long-ruling Ch’oe military family had in 1258 been forced from power in Koryo; their civilian successor in 1259 acknowledges Mongol suzerainty.

The treaty permits the sovereign power and traditional cultures of Goryeo, and implies that the Mongols have given up controlling Goryeo by direct rule.

The Chinese official Li Zengbo writes in his Kozhai Zagao, Xugaohou that the city of Qingzhou is manufacturing one to two thousand strong iron-cased gunpowder bomb shells a month during the Song dynasty's war with the Mongols, dispatching to Xiangyang and Yingzhou about ten to twenty thousand such bombs at a time.

Möngke’s sudden death from dysentery during the campaign against the Song fortress of Hezhou leads to another succession crisis, as Kublai and his younger brother Ariq Böge, sons of Genghis Khan’s son Tolui, both claim the Mongol throne.

Arigböge, supported by the traditionalists who distrust Kublai’s modernizing bent, summons a kuriltai at Karakorum, about two weeks after a similar event convoked by Kublai at Zhongdu.

Both are elected supreme ruler, or khakhan.

Kublai sends an army toward Karakorum, but Ariq Böge retreats westward with his forces.

The two Mongol armies clash, then withdraw without a decisive settlement.

The Kingdom of Denmark had reached a high point during the reign of Valdemar II, who had forged a Danish "Baltic Sea Empire", which by 1221 extended control from Estonia in the east to Norway in the north.

In this period, several of the "regional" law codes had been given; notably the Code of Jutland from 1241, which asserts several modern concepts like right of property; "that the king cannot rule without and beyond the law"; "and that all men are equal to the law".

Following the death of Valdemar II in 1241, the kingdom is in general decline due to internal strife and the rise of the Hanseatic League.

The competition between Valdemar’s sons—Erik IV “Plough-tax,” Abel, Duke of Schleswig, and Christopher I—will have the long term result that the southern parts of Jutland will become separated from the kingdom of Denmark and become semi-independent vassal duchies/counties.

Eric was supposedly murdered by his brother Abel in 1250; Christopher, elected King upon the death of his older brother Abel in the summer of 1252, has spent most of his reign trying to fight his many opponents.

By accepting Abel's sons as rulers of South Jutland, he has prevented their demands on the throne but in return the border district is now more or less independent.

He has also had to be reconciled with the kings of Norway and Sweden, who had been provoked by Abel's interventions.

Finally, he has had to yield to some of the political demands of the Danish magnates.

The Danehof seems to have become an institution during his rule.

Christopher’s men had arrested and humiliated the proud and self-righteous Archbishop Jakob Erlandsen after Erlandsen had refused to recognize Christopher's son, Eric, as his (Christopher's) rightful successor.

While trying to have his brother Eric canonized, Christopher finds himself excommunicated from the Catholic Church, but the excommunication has little or no effect.

Dying very "unexpectedly" and shortly after taking the Holy Communion on May 29, 1259, Christopher is buried in consecrated ground by the Bishop of Ribe.

His son succeeds him as Eric V under the auspices of his mother, the competent Queen Dowager Margaret Sambiria.

Eric's succession overrides the rights of the descendants of earlier monarchs, counter to the dictates of agnatic seniority.

However, since the reputations of the sons of Abel of Denmark are tainted by acts of fratricide and murder, it is relatively easy to ignore their claims to the throne.

Eric’s accession leads to what will be serious rivalry for generations, yet Christopher's line will be able to successfully retain their claim to the Danish throne.

The Mongols raid Bitom, one of the oldest cities of Upper Silesia.

Chartered by Bohemia only five years earlier, the city had grown owing to its location on a strategic crossroads.

(The city, slowly Germanized from the fourteenth century, will become known as Beuthen but will see its German population expelled in the aftermath of the Second World War.

Today known as Bytom, it is one of the main cities of Poland’s Upper Silesian Metropolitan Union.)

Invading Tatar forces led by Nogai Khan, a promising nephew of Berke who has become an ambitious and powerful warlord, plunder several villages of northern Poland during the rule of Boleslaw V, and such cities as Kraków, ...

…Zawichost, …

…Sandomierz, and other cities with the famous Mongol general Burundai, who had led the force that had overcome the resistance of Danylo of Halych earlier in the year.

The Nicaea Empire has not dissipated its strength by stretching the frontiers into Europe, for the possession of Thessalonica balances that of Nicaea.