Constantine III Leichoudes was the Ecumenical Patriarch of Constantinople from 1059 to 1063.

Born in Constantinople

Constantinople

Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

, he was a fellow student of Michael Psellos

Michael Psellos

Michael Psellos or Psellus was a Byzantine monk, writer, philosopher, politician and historian...

 and John Xiphilinus

John Xiphilinus

Joannes Xiphilinus , epitomator of Dio Cassius, lived at Constantinople during the latter half of the 11th century AD. He was a monk and the nephew of Patriarch John VIII of Constantinople, a well-known preacher ....

. He rose to high court offices: appointed protovestiarios

Protovestiarios

Protovestiarios was a high Byzantine court position, originally reserved for eunuchs.-History and functions:The title is first attested in 412, as the comes sacrae vestis, an official in charge of the Byzantine emperor's "sacred wardrobe" , coming under the praepositus sacri cubiculi...

, he later became proedros

Proedros

Proedros was a senior Byzantine court and ecclesiastic title in the 10th to mid-12th centuries. The female form of the title is proedrissa .-Court dignity:...

("president") of the Senate

Byzantine Senate

The Byzantine Senate or Eastern Roman Senate was the continuation of the Roman Senate, established in the 4th century by Constantine I. It survived for centuries but was increasingly irrelevant until its eventual disappearance in the 13th century....

 and was one of the senior aides of emperors Michael V

Michael V

Michael V "the Caulker" or Kalaphates , , was Byzantine emperor for 4 months in 1041–1042, as the nephew and successor of Michael IV and the adoptive son of his wife, the Empress Zoe.Michael V was the son of Stephen by Maria, a sister of Emperor Michael IV...

 and Constantine IX. He also became abbot

Abbot

The word abbot, meaning father, is a title given to the head of a monastery in various traditions, including Christianity. The office may also be given as an honorary title to a clergyman who is not actually the head of a monastery...

 of the imperial Mangana Monastery, and in 1059, following the dismissal of Michael I Cerularius

Michael I Cerularius

Michael I Cerularius , also known as Michael Keroularios or Patriarch Michael I, was the Ecumenical Patriarch of Constantinople from 1043 to 1059.-Biography:...

, he was elected into the patriarchal office, which he held until his death. He is considered a saint

Saint

A saint is a holy person. In various religions, saints are people who are believed to have exceptional holiness.In Christian usage, "saint" refers to any believer who is "in Christ", and in whom Christ dwells, whether in heaven or in earth...

 of the Eastern Orthodox Church

Eastern Orthodox Church

The Orthodox Church, officially called the Orthodox Catholic Church and commonly referred to as the Eastern Orthodox Church, is the second largest Christian denomination in the world, with an estimated 300 million adherents mainly in the countries of Belarus, Bulgaria, Cyprus, Georgia, Greece,...

, and is commemorated on 29 July.