23 events the sources record for this year, grouped by region.
What happened
China (11)
Wang Jian, who defended Hezhou, circled the walls and held them firmly; his loyalty was judged foremost among the loyal officials of Shu, and he was generously rewarded. (History of Song (Songshi), Annals 宋史卷044 開慶元年)
In the ninth month, Jia Sidao submitted a memorial: the Yuan forces crossed the river at Shawukou in Huangzhou, and the court and the people were alarmed. (History of Song (Songshi), Annals 宋史卷044 開慶元年)
The siege of Hezhou was lifted, and Wang Jian was appointed Military Governor of the Yongyuan Army. (History of Song (Songshi), Annals 宋史卷044 開慶元年)
In the twelfth month, Jia Sidao reported that the siege of Ezhou had been lifted, and an order was issued to reward merit. (History of Song (Songshi), Annals 宋史卷044 開慶元年)
Xianzong crossed the Jizhua rapids, reached Shizi Mountain, and the next day urged fighting beneath the walls. (History of Yuan (Yuanshi), Annals 元史 卷3 憲宗 1259年 2月)
He left three thousand elite troops to hold the position and sent the rest to attack Chongqing. (History of Yuan (Yuanshi), Annals 元史 卷3 憲宗 1259年 7月)
Xianzong died at Diaoyu Mountain, in the ninth year of his reign, aged fifty-two. (History of Yuan (Yuanshi), Annals 元史 卷3 憲宗 1259年 7月)
They reached the city «یاو چو» (Diaoyucheng, Hezhou) and began the siege; at the end of the line is the figure «two tümen out of ten» (context damaged). (Rashid al-Din, Jami' al-tawarikh (Compendium of Chronicles) 87460_djvu.txt 줄 18443–18446)
In the summer when Möngke Qaan was besieging the aforementioned fortress, the army fell ill from the water and climate, and plague («وبا») spread. (Rashid al-Din, Jami' al-tawarikh (Compendium of Chronicles) 87460_djvu.txt 줄 18485–18488)
When the Mongols attack Gian Fortress of the castle lord, the Byeolcho fights at night together with the people inside the castle and wins a great victory. (Goryeosa (History of Goryeo) 世家 卷24 高宗 四十六年)
West Asia (3)
Emperor Michael winters at Lampsakos and sets out for Constantinople in spring. (George Akropolites, History c.83 · L1153–1154)
The summer quarters are where Chinggis Khan fell ill and died during the Kitai campaign; in autumn they headed to «بیسون قبلقه» (partly damaged). (Rashid al-Din, Jami' al-tawarikh (Compendium of Chronicles) 87460_djvu.txt 줄 18047–18050)
He was buried in a place called «قوروق» (Qoruq, the forbidden ground), beside Chinggis Khan and Tolui Khan; this is the last passage of Möngke's section, presumably about Möngke. (Rashid al-Din, Jami' al-tawarikh (Compendium of Chronicles) 87460_djvu.txt 줄 18587–18589)
Southern Europe (7)
The sebastokrator John takes the fortress of Deabolis after a siege and its surrender. (George Akropolites, History c.80 · L840–842)
In the battle near Platamon, Manfred's auxiliary force (about 400 horsemen) is routed and its commanders taken prisoner. (George Akropolites, History c.81 · L1014–1015)
Strategopoulos and Raoul cross the Pindus mountains to Arta and take Arta (the situation later reverses). (George Akropolites, History c.82 · L1068–1071)
Nikephoros and his son John's side drive the imperial forces out of the Arta region and lift the siege of Ioannina. (George Akropolites, History c.82 · L1111–1116)
The emperor camps at Galata north of Constantinople, prepares to attack and contacts the collaborator Aselos. (George Akropolites, History c.83 · L1189–1190)
Three Latin envoys ask for peace, and the emperor grants a truce of a little over a year. (George Akropolites, History c.83 · L1201–1203)
Eastern Europe & Russia (1)
Tatar commanders Berkai and Kasachik come to Novgorod with their wives and conduct a census. (Novgorod First Chronicle litopys 기사 1259년)