What happened in 1270? — events across the world

West Asia

Outbreak of the Byzantine–Ottoman wars
1265–1479Anatolia
Around 1265, the first of a series of military conflicts broke out between the Byzantine Empire and the emerging Ottoman Empire over Anatolia. This clash initiated a war that lasted over two centuries, ultimately leading to the fall of the Byzantine Empire and the rise of the Ottoman Empire.
SourcesWikipedia ↗Image: Originally uploaded by Gabr-el (Transferred by terraflorin ) / Public domain ↗
Launch of the First Crusade
1095–1291Jerusalem
In November 1095, Pope Urban II officially called for Christians to take up arms and reconquer Jerusalem at the Council of Clermont, launching the First Crusade and inaugurating a series of crusades that continued until 1291. The call promised spiritual rewards, and the success led to the establishment of four Crusader states in the Levant.
SourcesWikipedia ↗Image: anonymus / Public domain ↗
Mongol invasions of Anatolia
1241–1335
The Mongol invasions of Anatolia began in 1241 with attacks on the city of Kâlin, culminating in the Battle of Köse Dağ in 1243. After the Seljuk defeat, the Sultanate of Rum submitted, and the Mongols assumed control over Anatolia. In 1255, following repeated Seljuk rebellions, Mongol forces swept through central and eastern Anatolia and stationed a garrison near Ankara. Their effective rule lasted until the collapse of the Ilkhanate in 1335.
SourcesWikipedia ↗

Mongol conquest of China begins
1205–1279Western Xia
In the early 13th century, the Mongol Empire under Genghis Khan initiated small-scale raids into Western Xia in 1205 and 1207, marking the beginning of a decades-long conquest of China. The conflict later escalated into full-scale campaigns against various Chinese dynasties.
SourcesWikipedia ↗Image: Sayf al-Vâhidî. Hérât. Afghanistan / Public domain ↗
Construction of Beiyue Temple
1270
Around the 13th century, a Taoist temple, Beiyue Temple, was built in Quyang, Hebei, China. The temple includes the Dening Hall, which is the largest, earliest, and one of the most important extant wooden buildings from the Yuan dynasty. The complex also contains three gates, an octagonal pavilion, and numerous ancient stelae.
SourcesWikipedia ↗Image: User:Zeus1234 / CC BY-SA 3.0 ↗

Eighth Crusade
1270Tunis
In 1270, the Crusaders reached Tunis, where King Louis IX soon died of illness and little fighting occurred. A Treaty of Tunis was negotiated: no territorial changes, but some commercial and political rights for Christians. The Crusaders then withdrew to Europe.
SourcesWikipedia ↗Image: Anonymous Unknown author / Public domain ↗

Mongol invasions and conquests
1206–1337Karakorum, Mongol Empire capital
After the founding of the Mongol Empire in the early 13th century, Genghis Khan and his descendants launched a series of expansion wars across Eurasia, creating the largest contiguous land empire in history within a century and profoundly reshaping the political landscape of Eurasia.
SourcesWikipedia ↗Image: Sayf al-Vâhidî. Hérât. Afghanistan / Public domain ↗

Construction of Malbork Castle begins
1270World Heritage
The Teutonic Knights began constructing Malbork Castle around the late 13th century, later expanding it into their headquarters. Located in present-day Malbork, Poland, it is the world's largest castle by land area and a UNESCO World Heritage Site.
SourcesUNESCO World Heritage listing ↗Wikipedia ↗Image: DerHexer ; derivate work: Carschten / CC BY-SA 3.0 ↗

These are known only to the century, not to the year. They are listed separately so a rough date is never mistaken for an exact one.