Timur has ruthlessly subdued Persia to the Euphrates River by 1387.

Of note during the Persian campaign is the capture of Isfahan.

When Isfahan surrenders to Timur in 1387, he treats it with relative mercy as he normally does with cities that surrender.

However, after the city revolts against Timur's taxes by killing the tax collectors and some of Timur's soldiers, Timur orders the massacre of the city's citizens; the death toll is reckoned at between one hundred thousand and two hundred thousand.

An eyewitness counts more than twenty-eight towers constructed of about fifteen hundred heads each.

His massacres are selective and he spares the artistic and technical (e.g, engineers) elites.