— In the Catacombs and elsewhere is to be found a monogram in the forms < >, composed of the Greek letters X and P, the initial letters of the name Χριστός, Christ. Sometimes the Greek letters α, ω (Alpha and Omega, the first and the last) are combined with the others, in the form α ω , or suspended by chains from the transverse bar, thus < >. The precise date of its origin is unknown; but Killen (Ancient Church, p. 317, note) asserts that it is found on coins of the Ptolemies, and cites Aringhi (Roma Subterranea, 2:567) as his authority. But, whatever the origin of the monogram, it came into new prominence and wider use from the fact that Constantine (A.D. 312) applied it to the heathen military standard. (See LABARUM). It is called, therefore, not only the monogram of Christ, but sometimes also the monogram of Constantine. — Schaff, Ch. History, 2:27; Jamieson, History of our Lord in Art, 2:315; Martigny, Dict. des Antiquites, p. 414; Perret, Les Catacombes de Rome, 3:96. (See CATACOMBS).
The Cyclopedia of Biblical, Theological, and Ecclesiastical Literature was edited by John McClintock and James Strong. It contains nearly 50,000 articles pertaining to Biblical and other religious literature, people, creeds, etc. It is a fantastic research tool for broad Christian study.
John McClintock was born October 27, 1814 in Philadelphia to Irish immigrants, John and Martha McClintock. He began as a clerk in his father's store, and then became a bookkeeper in the Methodist Book Concern in New York. Here he converted to Methodism and considered joining the ministry. McClintock entered the University of Pennsylvania in 1832 and graduated with high honors three years later. Subsequently, he was awarded a doctorate of divinity degree from the same institution in 1848.WikipediaRead More