In 1347, however, after a vicious civil war, their protector, John Cantacuzenus, entered Constantinople and forced his opponents to crown him co-emperor. In February 1347, a fourth synod was held which deposed the patriarch, John XIV, and excommunicated Akindynos. Isidore Buchiras, who had been excommunicated by the third synod, was now made patriarch. In the same month, the Barlaamite party held a competing synod which refused to acknowledge Isidore and excommunicated Palamas. Akindynos having died in 1348, Nicephorus Gregoras became the chief opponent of Hesychasm.