Tabriz also saw a gunpowder factory and a munitions depot. The training continued with constant drilling by British advisers, with a focus on the infantry and artillery. He received his opportunity to test his newly reformed military when the Ottoman–Persian War (1821–1823) began, and they proved themselves adept with several victories. This resulted in a peace treaty signed in 1823 after the Battle of Erzurum. The war was a victory for Persia, especially considering they were outnumbered, and this gave much needed confidence to his forces. His second war with Russia, which began in 1826, started off on a good note as he won back most of the territory lost in the Russo-Persian War (1804–1813); however it ended in a string of costly defeats after which Persia was forced to cede the last of its Caucasian territories, comprising all of what is modern day Armenia, Nakhchivan, the rest of the remainder of the contemporary Azerbaijani Republic that was still in Iranian hands, and Iğdır Province, all conform the 1828 Treaty of Turkmenchay. The eventual loss was due less to his and his armies skill and more to do with lack of reinforcements and overwhelming superiority in numbers. The irrevocable losses, which in total amounted up for all of Qajar Iran's territories in the North Caucasus and the South Caucasus, affected Abbas Mirza severely and his health began to suffer. He also lost enthusiasm for any more military reform. In 1833, he sought to restore order in Khorasan province, which was nominally under Persian supremacy, and while engaged in the task died at Mashhad in 1833. In 1834, his eldest son, Mohammed Mirza, succeeded Fath Ali Shah as the next king. R. G. Watson (History of Persia, 128–9) described him as “the noblest of the Qajar race”. He is most remembered for his valor in battle and his failed attempts to modernize the Persian army. He was not successful in part due to the lack of government centralization in Iran during the era. Furthermore, it was Abbas Mirza who first dispatched Iranian students to Europe for a western education. He was unable to prove successful in the long run in his wars with Russia as he ended up losing more territory than he gained. In popular culture Tabriz in Fog: an Iranian historical drama about Abbas Mirza's life. Sons Prince Mohammed Mirza, to become Mohammad Shah Qajar Prince Bahram Mirza Mo'ez