Conquest of Khorasan

The conquest of Khorasan took place in 31 AH. Hazrat Abdullah (ra) bin Aamir set out towards Khorasan and conquered Abarshar, Tus, Abiward and Nesa, until he reached up to Sarakhs. In the same year, the people of Merv formed a peace treaty.

(Muhammad Ibn Jarir al-Tabari, Tarikh al-Tabari, Vol. 5, Shukhus Abdillah bin Amir ila… [Beirut, Lebanon: Dar al-Fikr, 1998], p. 123)

Merv is in Turkmenistan and the other areas are situated in Iran. Expeditions towards Byzantine territories began in 32 AH. In 32 AH, Amir Mu‘awiyah (ra) fought against Byzantine territories and reached the shores of Constantinople.

(Ibn Kathir, Al-Bidayah wa al-Nihayah, Vol. 7, [Beirut, Lebanon: Dar al-Kutub al-‘Ilmiyyah, 2001] p. 155)