The Bactrian language is an extinct Eastern Iranian language which was spoken in the Central Asian region of Bactria. Linguistically, it is classified as belonging to the middle period of the East Iranian branch. Bactrian is closely related to Pashto, as well as Yidgha and Munji, and the medieval languages Sogdian, Khwarezmian and Parthian.

Because Bactrian was written predominantly with the Greek alphabet, Bactrian is sometimes referred to as "Greco-Bactrian", "Kushan" or "Kushano-Bactrian". In medieval times, Bactria was also known as Tocharistan, after the incoming Tokharoi tribes, and until the 1970s Bactrian was sometimes referred to as 'Eteo-Tocharian', but it is now certain that Bactrian is not closely related to the Tocharian languages, which do not belong to the Iranian language group. An older notion that the language of the Avesta represented (Old) Bactrian "had rightly fallen into discredit by the end of the 19th century" (Gershevitch 1983, p. 1250).

Following the conquest of Bactria by Alexander the Great in 323 BC, for about two centuries Greek was the administrative language of his Hellenistic successors, that is, the Seleucid and the Greco-Bactrian kingdoms. At some time after 124 BC, Bactria was overrun by Yuezhi (Tokharoi) tribes. Subsequently, one of the tribes advanced to found the Kushan dynasty in the 1st century AD.

Abu Bakr (Abdullah ibn Abi Quhafa) (Arabic: عبد الله بن أبي قحافة, Transliteration: ʿAbd Allāh ibn Abī Quḥāfah, c. 573 CE - 634 CE) also known as Abū Bakr as-Șiddīq (Arabic: أبو بكر الصديق) was a senior companion (Sahabi) and the father-in-law of the Islamic prophet Muhammad. He ruled over the Rashidun Caliphate from 632–634 CE when he became the first Muslim Caliph following Muhammad's death. As Caliph, Abu Bakr succeeded to the political and administrative functions previously exercised by Muhammad, since the religious function and authority of prophethood ended with Muhammad's death according to Islam. He was called Al-Siddiq (The Truthful) and was known by that title among later generations of Muslims.

As a young man, Abu Bakr became a cloth merchant and he traveled extensively in Arabia and neighboring lands in the Middle East, through which he gained both wealth and experience. He eventually came to be recognized as the chief of his clan. On his return from a business trip to Yemen, he was informed that in his absence Muhammad had openly declared his prophethood. Not long after, Abu Bakr accepted Islam and was the first person outside the family of Muhammad to openly become a Muslim. He was instrumental in the conversion of many people to the Islamic faith and early in 623, Abu Bakr's daughter Aisha was married to Muhammad, strengthening the ties between the two men.