Abu Ayyub rescued Mansur from this punishment and solidified a close relationship with the Caliph. Nevertheless, after appointing him as vizier, Mansur suspected Abu Ayyub of various crimes, including extortion and treachery, which led to the latter's assassination. The vacant secretary role was granted to Aban ibn Sadaqa until the death of the Caliph. In 757 AD, Mansur sent a large army to Cappadocia which fortified the city of Malatya. In this same year, he confronted a group of the Rawandiyya from the region of Greater Khorasan that were performing circumambulation around his palace as an act of worship. The confrontation turned violent and Al Mansur was graciously saved by former Umayyad general Ma'n ibn Za'ida al-Shaybani, who had, prior to this event, gone into hiding following the Abbasid Revolution. The Abbasids had previously accepted the support of the Rawandiyya prior to their uprising, but, after rising to power, the Caliphate cut ties with them because of their unorthodox beliefs. Al-Mansur was disconcerted by the Rawandiyya insurgency, and in 762, he founded the new imperial residence and palace city Madinat as-Salam (the city of peace), which became the core of the Imperial capital Baghdad. This was in response to a growing concern from the chief towns in Iraq, Basra, and Kufa that there was lack of solidity within the regime after the death of Abu'l 'Abbas (later known as as-Saffah). Another reason for the construction of the new capital was the growing need to house and provide stability for a rapidly developing Abbasid bureaucracy forged under the influence of Iranian ideals. Mansur even considered using ruins from the last Iranian capital, Ctesiphon, in the construction of Baghdad. In 767 AD, Mansur routed another revolt in Khorasan, the leader of which claimed to be a prophet. During his reign, Islamic literature and scholarship began to emerge in full force, supported by the Abbasid promotion of scholarly research, best exemplified by the Abbasid-sponsored Translation Movement. It was under al-Mansur that a committee, mostly made up of Syriac-speaking Christians, was set up in Baghdad with the purpose of translating extant Greek works into Arabic. Due to the Abbasid orientation toward the East, many Persians came to play a crucial role in the Empire, both culturally and politically.