Yazid was the son of a Persian princess who had been given as a concubine to Caliph al-Walid I. His mother was Shah-i Afrid, a daughter of Peroz. Al-Tabari quotes a couplet of Yazid's on his own ancestry: Tabari further records descriptions of Yazid as being tall and handsome.
Rebellion
During the reign of his cousin al-Walid II, Yazid spoke out against Walid's "immorality" which included discrimination on behalf of the Banu Qays Arabs against Yemenis and non-Arab Muslims, and Yazid received further support from the Qadariya and Murji'iya. Yazid slipped into Damascus and deposed Walid in a coup, following this up with a disbursement of funds from the treasury. According to Yazid's own account, Yazid sent Abd al-Aziz ibn al-Hajjaj to meet Walid at al-Bakhra'. 'Abd al-Aziz offered to set up a tribal assembly to decide the future of the realm. Walid rejected this offer and attacked, by which action he lost his life. Yazid had Walid's head hoisted "on a lance and paraded around Damascus"; Yazid then imprisoned Walid's sons 'Uthman and Hakam, whom Walid had designated as his heirs. On accession, Yazid explained that he had rebelled on behalf of the Book of Allah and the Sunna of His Prophet, and that this entailed ensuring that the strong not prey upon the weak. He promised "to engage in no building works, squander no money on wives or children, transfer no money from one province to another" without reason, "keep no troops on the field too long", and not to overtax the ahl al-dhimma; instead, he would eschew discrimination and would make his payments on time. He promised abdication if he failed to meet these goals, and held in principle to al-amr shura – to an elected caliphate. Tabari records Yazid's nickname "the Diminisher ", given because he reduced military annuities by 10%, whereas his predecessor had promised a raise. According to Islamic popular tradition, recorded in an apocalyptic style, Yazid would go himself into the marketplace. The city ofHoms refused allegiance to Yazid, and there were several other dissident movements against him. Another cousin, Marwan ibn Muhammad ibn Marwan, governor of Armenia, had initially supported Walid and on Walid's death entered Iraq to avenge him. Marwan eventually rallied around Yazid.
Caliphate
Yazid appointed Mansur ibn Jumhur to replace Yusuf ibn 'Umar as governor of Iraq. On May 15, Yazid wrote a letter, preserved from oral sources in al-Mada'ini and in al-Baladhuri. It supports the Umayyad dynasty up to but not including "the enemy of Allah" al-Walid II, at which point it lays out Yazid's version of the event at al-Bakhra'. At the end, Tabari's rendition has Yazid exhorting the Iraqis to follow Mansur ibn Jumhur. Yusuf ibn 'Umar was subsequently imprisoned and later killed by the son of Khalid ibn 'Abdallah al-Qasri. Mansur attempted to dismiss the Khurasani governor Nasr ibn Sayyar, but Nasr refused to accept this. Facing opposition from Juday al-Kirmani, Nasr invited al-Harith ibn Surayj to return from his thirteen-year stay in Turgesh territory. Al-Harith arrived wearing a fine suit of armour the Khaqan had given him and gained the support of many people in Khurasan. Yazid named his brother Ibrahim as his successor. Yazid fell ill of a brain tumour and died on October 3 or 4, 744. Ibrahim duly succeeded him.
