While martial law is the will of the commanding officer, it may be his will to have it applied, so far as ordinary matters of litigation are concerned, by courts. For that purpose, when in occupation of enemy's territory, he may allow the courts previously existing under the government of the enemy to continue in the exercise of their functions as his temporary representatives; or he can institute new tribunals of local jurisdiction having the name and form of civil courts, and proceeding according to the ordinary rules of administrative justice. All such courts act really as his agents and subject to his control, but in practice he seldom interferes with their judgments. He cannot, however, in establishing such a temporary tribunal, give it the powers of an admiralty court over prize cases. The judgment _in rem_ of an admiralty court, condemning a captured ship as a lawful prize of war, is treated as conclusive all over the world; but this is because it is a decree of a competent court, properly established to administer a branch of maritime law which, in its main principles, is part of the law of nations and common to the world. No mere military court on enemy's territory occupies that position.[Footnote: Jecker _v._ Montgomery, 13 Howard's Reports, 498, 515.] This right of the military commander exists equally on foreign territory in military occupation and on domestic territory, when the ordinary courts of his country are not open. During our Civil War, in 1864, President Lincoln, as commander in chief of the army and navy, set up a "Provisional Court for the State of Louisiana," after the Southern portion of that State had been occupied by the national forces and martial law declared. Judge Charles A. Peabody of New York, who had been a justice of the Supreme Court of that State, was commissioned to hold it and to dispose of both civil and criminal causes. Its docket became at once a full one, and important litigation was transacted there with general acceptance until the close of the war.[Footnote: The Grapeshot, 9 Wallace's Reports, 129; Report of Am. Historical Association for 1892, 199.]