Jani Beg was a khan

Khan (title)

Khan is an originally Altaic and subsequently Central Asian title for a sovereign or military ruler, widely used by medieval nomadic Turko-Mongol tribes living to the north of China. 'Khan' is also seen as a title in the Xianbei confederation for their chief between 283 and 289...

 of the Golden Horde

Golden Horde

The Golden Horde was a Mongol and later Turkicized khanate that formed the north-western sector of the Mongol Empire...

 from 1342 to 1357, succeeding his father Uzbeg Khan

Uzbeg Khan

Sultan Mohammed Öz-Beg, better known as Uzbeg or Ozbeg , was the longest-reigning khan of the Golden Horde, under whose rule the state reached its zenith...

.

After putting two of his brothers to death, Jani Beg crowned himself in Saray-Jük

Saray-Jük

Saray-Jük or Saraychyq was a medieval city on the border between Europe and Asia in the 10th-16th centuries. It was located on the Ural River, modern Kazakhstan, Atyrau Province, near Sarayshyq village, 50 km above Atyrau...

. He is known to have actively interfered in the affairs of Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n principalities and of Lithuania

Lithuania

Lithuania , officially the Republic of Lithuania is a country in Northern Europe, the biggest of the three Baltic states. It is situated along the southeastern shore of the Baltic Sea, whereby to the west lie Sweden and Denmark...

. The Grand Prince

Grand Prince

The title grand prince or great prince ranked in honour below emperor and tsar and above a sovereign prince .Grand duke is the usual and established, though not literal, translation of these terms in English and Romance languages, which do not normally use separate words for a "prince" who reigns...

s of Moscow

Moscow

Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

, Simeon Gordiy

Simeon of Russia

Simeon Ivanovich Gordyi was Prince of Moscow and Grand Prince of Vladimir. Simeon continued his father's policies of supporting the Golden Horde and acting as its leading enforcer in Russia. Simeon's rule was marked by regular military and political standoffs against Novgorod Republic and...

, and Ivan II

Ivan II of Russia

Ivan II Ivanovich the Fair was the Grand Prince of Moscow and Grand Prince of Vladimir in 1353. Until that date, he had ruled the towns of Ruza and Zvenigorod...

, were under constant political and military pressure from Jani Beg.

Jani Beg commanded a massive Crimean Tatar force that attacked the Crimean port city of Kaffa in 1343. The siege was lifted by an Italian relief force in February. In 1345 Jani Beg again besieged Kaffa, however, his assault was again unsuccessful due to an outbreak of the Black Plague among his troops. It is thought that Jani Beg's army catapulted infected corpses into Kaffa in an attempt to use the Black Death to weaken the defenders. Infected Genoese sailors subsequently sailed from Kaffa to Genoa, introducing the Black Death into Europe.

In 1356 Jani Beg conducted a military campaign in Azerbaijan

Azerbaijan

Azerbaijan , officially the Republic of Azerbaijan is the largest country in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded by the Caspian Sea to the east, Russia to the north, Georgia to the northwest, Armenia to the west, and Iran to...

 and conquered the city of Tabriz

Tabriz

Tabriz is the fourth largest city and one of the historical capitals of Iran and the capital of East Azerbaijan Province. Situated at an altitude of 1,350 meters at the junction of the Quri River and Aji River, it was the second largest city in Iran until the late 1960s, one of its former...

, installing his own governor there. He also asserted Jochid dominance over the Chagatai Khanate

Chagatai Khanate

The Chagatai Khanate was a Turko-Mongol khanate that comprised the lands ruled by Chagatai Khan , second son of the Great Khan Genghis Khan, and his descendents and successors...

, attempting to unite the three khanate

Khanate

Khanate, or Chanat, is a Turco-Mongol-originated word used to describe a political entity ruled by a Khan. In modern Turkish, the word used is kağanlık, and in modern Azeri of the republic of Azerbaijan, xanlıq. In Mongolian the word khanlig is used, as in "Khereidiin Khanlig" meaning the Khanate...

s of the Mongol Empire

Mongol Empire

The Mongol Empire , initially named as Greater Mongol State was a great empire during the 13th and 14th centuries...

. After accepting surrender from Shaikh Uvais

Shaikh Uvais

Shaikh Uvais, also known as Uways or Oways , was a Jalayirid ruler of Iraq and Azerbaijan . He was the son of Hasan Buzurg and the Chobanid Delsad Katun.-Life:...

, Janibeg boasted that three uluses (districts) of the Mongol Empire

Mongol Empire

The Mongol Empire , initially named as Greater Mongol State was a great empire during the 13th and 14th centuries...

 were under his control. Soon after this, Jani Beg faced an uprising in Tabriz resulting in the rise to power of the Jalayirid Dynasty

Jalayirids

The Jalayirids were a Mongol Jalayir dynasty which ruled over Iraq and western Persia after the breakup of the Mongol Khanate of Persia in the 1330s....

, an offshoot of Ilkhanate

Ilkhanate

The Ilkhanate, also spelled Il-khanate , was a Mongol khanate established in Azerbaijan and Persia in the 13th century, considered a part of the Mongol Empire...

 and, ultimately, in the death of the Khan.

Russia's Chudov Monastery

Chudov Monastery

The Chudov Monastery was founded in the Moscow Kremlin in 1358 by Metropolitan Alexius of Moscow. The monastery was dedicated to the miracle of the Archangel Michael at Chonae...

, founded at about the time of Jani Beg's fall by Metropolitan Aleksii and Sergei of Radonezh was built on land that, according to legend, the Khan had granted to Aleksii as thanks for the miraculous curing of his wife, Taidula, by the latter.

The reign of Jani Beg was marked by the first signs of the feudal strife which would eventually contribute to the demise of the Golden Horde. Jani Beg's assassination in 1357 opened a quarter-century of political turmoil within the Golden Horde. Twenty-five khans succeeded each other between 1357 and 1378.