Question: What is the name of the Australian Footballer who was a person held in custody by a belligerent power during the armed conflict, World War I?

Context paragraphs:
Prisoner of war: A prisoner of war (POW, PoW, PW, P/W, WP, PsW, enemy prisoner of war (EPW) or "missing-captured") is a person, whether combatant or non-combatant, who is held in custody by a belligerent power during or immediately after an armed conflict.  The earliest recorded usage of the phrase "prisoner of war" dates to 1660.

Unlawful combatant: An unlawful combatant, illegal combatant or unprivileged combatant/belligerent is a person who directly engages in armed conflict in violation of the laws of war.  An unlawful combatant may be detained or prosecuted under the domestic law of the detaining state for such action, subject of course to international treaties on justice and human rights.

Insurgency: Not all rebellions are insurgencies.  There have been many cases of non-violent rebellions, using civil resistance, as in the People Power Revolution in the Philippines in the 1980s that ousted President Marcos and the Egyptian Revolution of 2011.  Where a revolt takes the form of armed rebellion, it may not be viewed as an insurgency if a state of belligerency exists between one or more sovereign states and rebel forces.  For example, during the American Civil War, the Confederate States of America was not recognized as a sovereign state, but it was recognized as a belligerent power, and thus Confederate warships were given the same rights as United States warships in foreign ports.

Enemy combatant: Enemy combatant is a term referring to a person who, either lawfully or unlawfully, directly engages in hostilities for an enemy state or non-state actor in an armed conflict.  Prior to 2008, the definition was: "Any person in an armed conflict who could be properly detained under the laws and customs of war."  In the case of a civil war or an insurrection the term "enemy state" may be replaced by the more general term "Party to the conflict" (as described in the 1949 Geneva Conventions ).

Non-combatant: Non-combatant is a term of art in the law of war and international humanitarian law, describing civilians who are not taking a direct part in hostilities; persons—such as combat medics and military chaplains—who are members of the belligerent armed forces but are protected because of their specific duties (as currently described in Protocol I of the Geneva Conventions, adopted in June 1977); combatants who are placed "hors de combat"; and neutral nationals (including military personnel) who are not fighting for one of the belligerents involved in an armed conflict.  This particular status was first recognized under the Geneva Conventions with the First Geneva Convention of 1864.

Prisoner-of-war camp: A prisoner-of-war camp is a site for the containment of enemy combatants captured by a belligerent power in time of war.  It should be noted that there are significant differences among POW camps, internment camps, and military prisons. Purpose built prisoner-of-war camps appeared at Norman Cross in England in 1797 and HM Prison Dartmoor, both constructed during the Napoleonic Wars, and they have been in use in all the main conflicts of the last 200 years.  The main camps are used for coast guards, marines, sailors, soldiers, and more recently, airmen of an enemy power who have been captured by a belligerent power during or immediately after an armed conflict.  In addition, non-combatants, such as merchant mariners and civilian aircrews, have been imprisoned in some conflicts.  With the adoption of the Geneva Convention on the Prisoners of War in 1929, later superseded by the Third Geneva Convention, prisoner-of-war camps have been required to be open to inspection by authorized representatives of a neutral power.  Not all belligerents have consistently applied the convention in all conflicts.

International humanitarian law: International humanitarian law (IHL) is the law that regulates the conduct of war ("jus in bello").  It is that branch of international law which seeks to limit the effects of armed conflict by protecting persons who are not participating in hostilities, and by restricting and regulating the means and methods of warfare available to combatants. IHL is inspired by considerations of humanity and the mitigation of human suffering.  "It comprises a set of rules, established by treaty or custom, that seeks to protect persons and property/objects that are (or may be) affected by armed conflict and limits the rights of parties to a conflict to use methods and means of warfare of their choice".  It includes "the Geneva Conventions and the Hague Conventions, as well as subsequent treaties, case law, and customary international law".  It defines the conduct and responsibilities of belligerent nations, neutral nations, and individuals engaged in warfare, in relation to each other and to "protected persons", usually meaning non-combatants.  It is designed to balance humanitarian concerns and military necessity, and subjects warfare to the rule of law by limiting its destructive effect and mitigating human suffering.

Billy Stewart (Australian footballer): Billy Stewart (3 August 1884 – 16 April 1968) was an Australian rules footballer who played with St Kilda in the Victorian Football League (VFL).  Stewart also played for the Victorian team at the 1908 Melbourne Carnival, replacing an injured player.  He played his last VFL game in a victory against Geelong, before transferring to Prahran in the Victorian Football Association.  He would later also play for North Ballarat.  Serving for Australia in World War I, he spent time as a Prisoner of war in Germany.

Civilian: A civilian is someone who is not a member of any military group and does not take a direct part of hostilities in times of armed conflict, as defined by the laws of war (and international humanitarian law).  The term "civilian" is slightly different from a non-combatant under the laws of war, as some non-combatants are not civilians (for example, military chaplains attached to the belligerent armed forces or neutral military personnel).  Under international law, civilians in the territories of a party to an armed conflict are entitled to certain privileges under the customary laws of war and international treaties such as the Fourth Geneva Convention.  The privileges that they enjoy under international law depends on whether the conflict is an internal one (a civil war) or an international one.

POW (disambiguation): POW is "prisoner of war", a person, whether civilian or combatant, who is held in custody by an enemy power during or immediately after an armed conflict.

Supporting paragraphs: Billy Stewart (Australian footballer) Prisoner of war
Answer: Billy Stewart (3 August 1884 – 16 April 1968)