Short answers, pulled from the story.
Nader Shah was born in November 1688 into a humble pastoral family in Darra Gaz in the mountains north of Mashad. He belonged to the Qirqlu branch of the Afshar Turkmen and his father was a herdsman of lowly but respectable status.
Nader Shah crushed the Mughal army in less than three hours at the large Battle of Karnal on the 13th of February 1739. Following this decisive victory, he captured the Mughal ruler Muhammad Shah and entered Delhi.
The Afsharid dynasty ended in 1796 when Mohammad Khan Qajar seized Mashhad and tortured Shahrokh to force him to reveal the whereabouts of Nader Shah's treasures. Shahrokh died of his injuries soon after and with him the Afsharid dynasty came to an end.
Nader Shah proposed that Iran adopt a form of Shi'a Islam called Ja'fari in honour of the sixth Shi'a Imam Ja'far al-Sadiq. He banned certain Shi'a practices offensive to Sunnis and consciously avoided using the color green which was associated with Shia Islam and the Safavid dynasty.
In 1740 Nader Shah conquered the Khanate of Khiva and forced the Uzbek khanate of Bukhara to submit. He also conquered Khwarezm on this expedition into Central Asia.
Nader Shah blinded his son Reza Qoli Mirza as punishment for an assassination attempt and later executed the nobles who witnessed the blinding. Reza Qoli Mirza was the eldest son of Nader Shah and had ruled Iran during his father's absence.