Short answers, pulled from the story.
Nader Qoli Beg was born in the fortress of Dastgerd located in the northern valleys of Khorasan province. His family lived a nomadic life among the Turkoman Afshar tribe before his father died when he turned thirteen years old.
Nader Shah became Shah of Iran on the 8th of March 1736 after being crowned at a grand meeting called qoroltai on Moghan plain. This event marked the end of two centuries Safavid rule and the beginning of the Afsharid dynasty.
The Battle of Karnal occurred on the 13th of February 1739 where Nader crushed an enemy force six times larger than his own within three hours. Following this victory Iranian troops entered Delhi and looted treasures worth seven hundred million rupees including the Koh-i-Noor diamond.
Nader Shah replaced Shia Islam with the Ja'fari school because he believed Safavid Shiaism intensified conflict with the Ottoman Empire. He aimed to weaken the Safavids since Shia Islam supported that dynasty strongly while also seeking revenue from pilgrimage trade.
Nader Shah was assassinated in June 1747 when conspirators broke into his sleeping quarters and killed him. His nephew Ali Qoli renamed Adel Shah succeeded him as king but was deposed within a year leading to the collapse of the empire.