Evagrius was a brilliant young deacon at Constantinople, preaching under Gregory of Nazianzus, when he fell in love with a married noblewoman and fled the city rather than face the consequences. He went to Jerusalem, was taken in by Melania the Elder, and from there to the Egyptian desert, where he spent the rest of his life among the monks of Nitria and Kellia, weaving baskets, eating very little, and writing in short numbered sentences.
The writing has two halves. One is the practical psychology, which everyone found useful. The other is a speculative theology, in the tradition of Origen, involving a pre-existent unity of minds, a fall into diversity, and an eventual restoration in which bodies and distinctions fall away. That second half was condemned. The Second Council of Constantinople in 553 anathematised Origenist propositions and named Evagrius among their sources, and his works stopped being copied under his name in Greek.
They did not stop being read. The practical works survived in Greek attributed to other authors, notably Nilus, and were read for centuries by people who did not know whose they were. The speculative works survived in Syriac and Armenian translations made before the condemnation, and were recovered by scholars in the twentieth century. His psychology reached the Latin West through Cassian, who transmits it faithfully and never names him, and it is in the Philokalia, so that a condemned author sits near the foundation of both Eastern and Western contemplative practice.