Short answers, pulled from the story.
Parthia sits in northeastern Iran with parts extending into southern Turkmenistan. The Kopet Dag mountain range forms a jagged northern wall for the territory while the Dasht-e Kavir desert stretches out to the south.
Cyrus the Great defeated Median Astyages one year before 520 BC. Parthia became one of the first provinces to acknowledge his rule immediately after that victory.
Arsaces led the Parni people from the Tajen River valley south-east of the Caspian Sea. About 238 BC, Arsaces and his brother Tiridates invaded Parthia under their command.
By the 2nd century AD, frequent wars with Rome and infighting among nobles weakened the Arsacids. The Persian Sassanids vanquished the Arsacids finally in April 224 after a long decline.
Nearly three thousand ostraca found at Nisa represent attested written Parthian use. This site served as wine storage within present-day Turkmenistan while additional fragments appear at Dura-Europos in Syria.