He was elected pope a few days after the death of his predecessor Pope Agatho, who died on January 10, 681 during a time when negotiations were under way concerning the relations of the imperial court of Constantinople with the elections of the pope. These negotiations included a reduction in the tax due Constantinople at the time of a papal consecration. This may have caused the delay in Leo's consecration until August 17, 682.
While Pope Leo's pontificate was short, the confirmation of the acts of the Sixth Ecumenical Council, that was held during his predecessor's term, fell to him. In his confirmation, Leo accepted with pleasure the condemnation of the Monothelite heresy. He also made clear that the condemnation of Pope Honorius was not for teaching the heresy but for his negligence in allowing it to spread. The papal acceptance of the acts of the council were confirmed by the church in the West during a synod in Toledo in 684.
After emperor Constantine IV revoked the privileges for Ravenna established by his father emperor Constans II as an imperial exarchate, Leo was also able to regularize papal relations with the archbishops of Ravenna, who had maintained an independence from Rome. Leo made the change more agreeable to Ravenna by abolishing the tax that they were accustomed paying to Rome when they received their pallium.
Pope Leo died on June 28, 683 and was buried in St. Peter's Cathedral.
