Skip to main content

Eusebius of Nicomedia

Eusebius of Nicomedia (yōōsē´bēəs, nĬkōmē´dēə), d. 342, Christian churchman and theologian, leader of the heresy of Arianism. He was bishop of Nicomedia (330–39) and patriarch of Constantinople (339–42); Eusebius was powerful because of his influence with Roman Emperor Constantine I and particularly with the emperor's son, Constantius II. He sheltered Arius in 321 and fought his condemnation at Nicaea (see Nicaea, First Council of). Eusebius signed the Nicene formulary but was exiled by Constantine shortly afterward. Eusebius' influence on the emperor's sister Constantia, however, soon won him his reprieve (328). As adviser to Constantius, a committed Arian, he systematically advanced a moderate Arianism throughout the empire.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Eusebius of Nicomedia." The Columbia Encyclopedia, 6th ed.. . 15 Jul. 2018 <>.

"Eusebius of Nicomedia." The Columbia Encyclopedia, 6th ed.. . (July 15, 2018).

"Eusebius of Nicomedia." The Columbia Encyclopedia, 6th ed.. . Retrieved July 15, 2018 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.