His All Holiness Athanasius I was the Patriarch of Constantinople for two periods: from 1289 to 1293 and from 1303 to 1309. He opposed the reunion efforts between Rome and Constantinople current at the time. During his first term he introduced some ecclesial reforms that were opposed by some of the clergy in Constantinople. He resigned in 1293, but, backed by popular support, he was restored to the patriarchal throne in 1303. During his second term as patriarch he was strongly opposed by the faction of pro-union clergy and was forced to retire in 1310.