Margiana is a historical region centred on the oasis of Merv and was a minor satrapy within the Achaemenid satrapy of Bactria, and a province within its successors, the Seleucid, Parthian and Sasanian empires.

Merv, also known as the Merve Oasis, formerly known as Alexandria, Antiochia in Margiana and Marw al-Shāhijān, was a major Iranian city in Central Asia, on the historical Silk Road, near today's Mary, Turkmenistan. Human settlements on the site of Merv existed from the 3rd millennium BC until the 18th century AD. It changed hands repeatedly throughout history. Under the Achaemenid Empire, it was the center of the satrapy of Margiana. It was subsequently ruled by the ancient Macedonians, Seleucids, Parthians, Sasanians, Arabs, Ghaznavids, Seljuqs, Khwarazmians and Timurids, among others.