After the death of Abu Sa'id, ruler of the Ilkhanate, in 1335, there was a power vacuum in Persia.
In the end, Persia was split amongst the Muzaffarids, Kartids, Eretnids, Chobanids, Injuids, Jalayirids, and Sarbadars.
In 1383, Timur started his lengthy military conquest of Persia, though he already ruled over much of Persian Khorasan by 1381, after Khwaja Mas'ud, of the Sarbadar dynasty surrendered.
Timur began his Persian campaign with Herat, capital of the Kartid dynasty.
When Herat did not surrender he reduced the city to rubble and massacred most of its citizens; it remained in ruins until Shah Rukh ordered its reconstruction.
Timur then sent a General to capture rebellious Kandahar.
With the capture of Herat the Kartid kingdom surrendered and became vassals of Timur; it would later be annexed outright less than a decade later in 1389 by Timur's son Miran Shah.

Timur then headed west to capture the Zagros Mountains, passing through Mazandaran.
During his travel through the north of Persia, he captured the then town of Tehran, which surrendered and was thus treated mercifully.
He laid siege to Soltaniyeh in 1384.
Khorasan revolted one year later, so Timur destroyed Isfizar, and the prisoners were cemented into the walls alive.
The next year the kingdom of Sistan, under the Mihrabanid dynasty, was ravaged, and its capital at Zaranj was destroyed.
Timur then returned to his capital of Samarkand, where he began planning for his Georgian campaign and Golden Horde invasion.
In 1386, Timur passed through Mazandaran as he had when trying to capture the Zagros.
He went near the city of Soltaniyeh, which he had previously captured but instead turned north and captured Tabriz with little resistance, along with Maragha.
He ordered heavy taxation of the people, which was collected by Adil Aqa, who was also given control over Soltaniyeh.
Adil was later executed because Timur suspected him of corruption.

Timur then went north to begin his Georgian and Golden Horde campaigns, pausing his full-scale invasion of Persia.
When he returned, he found his generals had done well in protecting the cities and lands he had conquered in Persia.
Though many rebelled, and his son Miran Shah, who may have been regent, was forced to annex rebellious vassal dynasties, his holdings remained.
So he proceeded to capture the rest of Persia, specifically the two major southern cities of Isfahan and Shiraz.
When he arrived with his army at Isfahan in 1387, the city immediately surrendered; he treated it with relative mercy as he normally did with cities that surrendered (unlike Herat).
However, after Isfahan revolted against Timur's taxes by killing the tax collectors and some of Timur's soldiers, he ordered the massacre of the city's citizens; the death toll is reckoned at between 100,000 and 200,000.
An eye-witness counted more than 28 towers constructed of about 1,500 heads each.
This has been described as a "systematic use of terror against towns...an integral element of Tamerlane's strategic element", which he viewed as preventing bloodshed by discouraging resistance.
His massacres were selective and he spared the artistic and educated.
This would later influence the next great Persian conqueror: Nader Shah.

Timur then began a five-year campaign to the west in 1392, attacking Persian Kurdistan.
In 1393, Shiraz was captured after surrendering, and the Muzaffarids became vassals of Timur, though prince Shah Mansur rebelled but was defeated, and the Muzafarids were annexed.
Shortly after Georgia was devastated so that the Golden Horde could not use it to threaten northern Iran.
In the same year, Timur caught Baghdad by surprise in August by marching there in only eight days from Shiraz.
Sultan Ahmad Jalayir fled to Syria, where the Mamluk Sultan Barquq protected him and killed Timur's envoys.
Timur left the Sarbadar prince Khwaja Mas'ud to govern Baghdad, but he was driven out when Ahmad Jalayir returned.
Ahmad was unpopular but got some dangerous help from Qara Yusuf of the Kara Koyunlu; he fled again in 1399, this time to the Ottomans.
After the death of Abu Sa'id, ruler of the Ilkhanate, in 1335, there was a power vacuum in Persia. In the end, Persia was split amongst the Muzaffarids, Kartids, Eretnids, Chobanids, Injuids, Jalayirids, and Sarbadars. In 1383, Timur started his lengthy military conquest of Persia, though he already ruled over much of Persian Khorasan by 1381, after Khwaja Mas'ud, of the Sarbadar dynasty surrendered. Timur began his Persian campaign with Herat, capital of the Kartid dynasty. When Herat did not surrender he reduced the city to rubble and massacred most of its citizens; it remained in ruins until Shah Rukh ordered its reconstruction. Timur then sent a General to capture rebellious Kandahar. With the capture of Herat the Kartid kingdom surrendered and became vassals of Timur; it would later be annexed outright less than a decade later in 1389 by Timur's son Miran Shah.
Timur then headed west to capture the Zagros Mountains, passing through Mazandaran. During his travel through the north of Persia, he captured the then town of Tehran, which surrendered and was thus treated mercifully. He laid siege to Soltaniyeh in 1384. Khorasan revolted one year later, so Timur destroyed Isfizar, and the prisoners were cemented into the walls alive. The next year the kingdom of Sistan, under the Mihrabanid dynasty, was ravaged, and its capital at Zaranj was destroyed. Timur then returned to his capital of Samarkand, where he began planning for his Georgian campaign and Golden Horde invasion. In 1386, Timur passed through Mazandaran as he had when trying to capture the Zagros. He went near the city of Soltaniyeh, which he had previously captured but instead turned north and captured Tabriz with little resistance, along with Maragha. He ordered heavy taxation of the people, which was collected by Adil Aqa, who was also given control over Soltaniyeh. Adil was later executed because Timur suspected him of corruption.
Timur then went north to begin his Georgian and Golden Horde campaigns, pausing his full-scale invasion of Persia. When he returned, he found his generals had done well in protecting the cities and lands he had conquered in Persia. Though many rebelled, and his son Miran Shah, who may have been regent, was forced to annex rebellious vassal dynasties, his holdings remained. So he proceeded to capture the rest of Persia, specifically the two major southern cities of Isfahan and Shiraz. When he arrived with his army at Isfahan in 1387, the city immediately surrendered; he treated it with relative mercy as he normally did with cities that surrendered (unlike Herat). However, after Isfahan revolted against Timur's taxes by killing the tax collectors and some of Timur's soldiers, he ordered the massacre of the city's citizens; the death toll is reckoned at between 100,000 and 200,000. An eye-witness counted more than 28 towers constructed of about 1,500 heads each. This has been described as a "systematic use of terror against towns...an integral element of Tamerlane's strategic element", which he viewed as preventing bloodshed by discouraging resistance. His massacres were selective and he spared the artistic and educated. This would later influence the next great Persian conqueror: Nader Shah.
Timur then began a five-year campaign to the west in 1392, attacking Persian Kurdistan. In 1393, Shiraz was captured after surrendering, and the Muzaffarids became vassals of Timur, though prince Shah Mansur rebelled but was defeated, and the Muzafarids were annexed. Shortly after Georgia was devastated so that the Golden Horde could not use it to threaten northern Iran. In the same year, Timur caught Baghdad by surprise in August by marching there in only eight days from Shiraz. Sultan Ahmad Jalayir fled to Syria, where the Mamluk Sultan Barquq protected him and killed Timur's envoys. Timur left the Sarbadar prince Khwaja Mas'ud to govern Baghdad, but he was driven out when Ahmad Jalayir returned. Ahmad was unpopular but got some dangerous help from Qara Yusuf of the Kara Koyunlu; he fled again in 1399, this time to the Ottomans.
Timur