Although the term chaplain originally had Christian roots,[1] it is generally used today in military organizations to describe all professionals specially trained to serve any spiritual need, regardless of religious affiliation.

In addition to offering pastoral care to individuals and supporting their religious rights and needs, military chaplains may also advise the executive[which?]

They may also liaise with local religious leaders in an effort to understand the role of religion as a factor both in hostility and war and in reconciliation and peace.

[7] British Army chaplains undertake seven-weeks training at The Armed Forces Chaplaincy Centre Amport House and the Royal Military Academy Sandhurst.

As the application process proceeds, and the military determines whether the applicant will meet standards in areas such as health, physical fitness, age, education, citizenship, past criminal history, and suitability for service, which includes supporting the free exercise of religion for men and women of all faiths, an endorsement from an endorsing agency that is recognized by the Department of Defense, representing one or more faith groups in the United States, will be required, in part to ensure that the separation of church and state is honored.

Neither the government as a whole nor the military in particular will be put into the position of determining whether an individual is a bona fide priest, minister, rabbi, imam, etc.

Crosby describes an incident where a US chaplain became a trained tank gunner and was removed from the military for this "entirely illegal, not to mention imprudent" action.

"[11] The Reverend Leslie Hardman, the British Second Army's senior Jewish chaplain, who became well known for his work amongst the liberated prisoners after the capture of Bergen-Belsen concentration camp, was another who insisted on being armed while on active service.

In 2006, training materials obtained by US intelligence showed that insurgent snipers fighting in Iraq were urged to single out and attack engineers, medics, and chaplains on the theory that those casualties would demoralize entire enemy units.

In some countries, like Israel, Canada, and South Africa, one chief of chaplains/chaplain general serves in that position for all chaplains of all religions, in all branches of the military.

While serving as a chaplain, the priest or deacon remains incardinated in his home diocese, but is temporarily under the direction of the prelate of the ordinariate for the duration of his service.

Badges and insignia vary widely across nations and services; though generally include some form of symbol specific to the individual chaplain's religion.

Roman Catholic military chaplains served in the Argentine armed forces since the early nineteenth century, and wore officers´ uniforms and ranks.

However, the use of these was discontinued in the 1970s in the Army and the Air Force, and in the 2000s in the Navy, due to allegations of some chaplains supposedly abusing their military position and thus discouraging their subordinates to approach them when in need.

[31] The inclusion of Afro-Brazilian religions was discussed in the judiciary, distinguished black militants asking for military chaplains in the Brazilian Armed Forces.

[33] Brazil adopted professional military chaplains only in World War II, during which 25 Catholic priests and 2 Protestant reverends gave religious assistance to 45,000 Brazilian soldiers in the Italian campaign.

In 1954, pastor Tissot was one of the last paratrooper volunteers to jump over the besieged Dien Bien Phu fortified camp in northern Vietnam.

Very few Jewish soldiers in the Prussian army of the 18th century left historical traces, e.g. Konstantin Nathanel of Salomon, who was promoted to general in 1760.

German soldiers during the Nazi era continued to belong to the churches and had the words "Gott mit uns" (God with us) on their belt buckles.

"Being a chaplain in the German army had always been a prestigious position and the Nazis wanted people who represented that old military tradition (..) and not sow discord or division.

"[49] The German military chaplains mostly wanted to bring the word of the Christian God to men in the field and to deliver the sacraments, make their families proud and serve their country.

Initially, a "military-chaplaincy" contract was only signed between the state and the Protestant Church, but was extended to all other religious communities for reasons of parity.

In the Netherlands, there are chaplains of Protestant, Catholic, Jewish, Muslim, Hindu, and humanist faiths, provided by the De Diensten Geestelijke Verzorging (DGV) or the Spiritual Care Services.

They may however, be addressed according to the practice of their religious bodies e.g., Father, Pastor, Umfundisi (Zulu and Xhosa), Moruti (Sotho), Dominee (Afrikaans) etc.

The purpose of utilizing these chaplains, according to Prime Minister of Ukraine Arseniy Yatsenyuk was to boost Ukrainian army morale during the conflict.

Land based chaplains appeared during the reign of King Edward I, although their duties included jobs that today would come under the jurisdiction of military engineers and medical officers.

In the Royal Navy, chaplains are traditionally addressed by their Christian name, or with one of many nicknames (Bish; Sin-Bosun; Devil Dodger; Sky-pilot etc.).

During World War II the head of chaplaincy in the British Army was an Anglican chaplain-general (a major-general), who was formally under the control of the Permanent Under-Secretary of State.

[77] Individual cases include that of Air Force Lt. Col. Garland Robertson, discharged in 1993 after expressing political opinions in a letter to the Abilene Reporter-News[78] and Navy Chaplain Lt. Gordon Klingenschmitt who, against direct orders to him personally, as well as military law and tradition, protested openly and publicly while in uniform against military policies which he believed restricted the free exercise of his religion.

One appellate case, Katcoff v. Marsh (1985) upheld the system as a permissible attempt to support service members in the "free exercise" of their religious beliefs, though others have described the details of the chaplaincy system as violations of the legal principles that the federal government maintain neutrality and avoid becoming entangled in religious affairs.