A chaplain is a person, generally a member of the clergy, who serves a group of people who are not formally organized as a mission, a parish, or a church, and who perform their duties by various attachments to military units, hospitals, prisons, schools, or other diverse organizations. The Orthodox Christian Church has provided such services since its inception through various means, varying with differing cultures and times, often through monastics.
The word chaplain itself appears to be of western European origin. The most commonly accepted source seems the story that associated the retained part of his cape after St. Martin of Tours had shared half his cape with a poorly dressed beggar in the city of Amiens. The remnant kept by St. Martin was called a capa or capella, and was kept after St. Martin’s repose by the kings of France who on military campaigns enshrined it in a traveling tent. This tent became known as the capella and the custodians of the relic became known as capellani: hence the word chaplain is derived through Middle English chapelein, from Old French chapelain, from Medieval Latin capellanus.
The most common use of the word chaplain within Orthodoxy, particularly for Orthodox living in countries of western European cultures, is in reference to priests as chaplains who are members of or associated with armed forces or are affiliated with hospitals, prisons, schools, hostels, and similar groups. These chaplains provide spiritual and pastoral support for their communities, including conducting religious services.