In the laws of the Franks and kindred tribes the word had three main uses: first in the general sense of a proclamation, secondly, for the fine incurred for disobeying such proclamation, and thirdly for the district over which proclamations were issued.
It was the frequent use of proclamations or bans, commanding or forbidding certain actions under a threat of punishment, which caused the second of these uses to arise out of the first, as the idea of wrong-doing became associated with the proclamation or ban. This bannum dominicum, as it was called, was employed by all feudal lords, from the king downwards, against offenders, and played an important part in the administration of justice in feudal times. It usually took the form of an order to make some amend for wrong-doing, which, if not complied with, was followed by the withdrawal of all protection from the offender, i.e. by outlawry.
After the break-up of the Carolingian empire another use of the word arose in France. "Ban" had occasionally been used in a restricted sense referring only to the summons calling out the host; and as France became separated from the Empire, French law and custom seized upon this use, and soon the men liable to military service were known as "the ban." A variant form of this word was heriban or ariban, and it is possible that some confusion between the early syllables of this word and the word arrière led to a distinction between the ban and the arrière-ban or retro-bannum. At all events this distinction arose; the ban referring to the vassals called out by the king, and the arrière-ban to the sub-vassals called upon by the vassals in their turn. As in England, the liability to military service was often commuted for a monetary payment, and there were various exemptions. In the 17th and 18th centuries the ban and arrière-ban were lacking in discipline when called out, and were last summoned in 1758. Local levies, however, called out between this date and the Revolution were sometimes referred to by these names.
In the medieval Empire and in Germany the word "ban" retained the special sense of punishment. The German equivalent of ban is Acht, and the sentence soon became practically one of outlawry. Connected possibly with the power enjoyed in earlier times by the assemblies of freemen of outlawing an offender, it was frequently used by the emperor, or German king, and the phrase "under the ban" is very common in medieval history. The execution of this sentence of placing an offender under the imperial ban, or Reichsacht, was usually entrusted to some prince or noble, who was often rewarded with a portion of the outlaw's lands. It was, however, only a serious punishment when the king or his supporters were strong enough to enforce its execution. Employed not only against individuals but also against towns and districts, it was sometimes divided into the Acht and the Oberacht, i.e. partial or complete outlawry. Documents of the time show that the person placed under the imperial ban drew down absolute destitution upon his relatives and frequently death upon himself.
At first this sentence was the act of the emperor or king himself, but as the Empire became more German, and its administration less personal, it was entrusted to the imperial aulic council (Reichshofrat), and to the imperial court of justice or imperial chamber (Reichskammergericht). These courts were deprived of this power in 1711, retaining only the right of suggesting its use. The imperial ban had, however, been used for the last time in 1706, when Maximilian Emanuel, elector of Bavaria, was placed under it.
There are many other uses of the word in the sense of a prohibition. In earlier French law the ban of wine or bannum vini, was the exclusive right of a lord to sell wine during a stated number of days, and the ban of March and April forbade the pasturing of cattle in certain fields during these months. There were also other similar uses dating from feudal times. In modern French law the phrase rupture de ban described, previous to 1885, the departure without notice of any released criminal living under the special surveillance of the police. The French government still retains the rights of appointing an obligatory place of residence for any criminal, and any escape from this place is a rupture de ban. A Scandinavian use of the word gives it the sense of a curse. This usage mingling with the use which spiritual lords shared with temporal lords of issuing the ban over their dependents, has become in a special sense ecclesiastical, and the sentence of excommunication is frequently referred to as "under the papal ban." The word is also used in this way by Shakespeare and Milton. The modern English use of the phrase "under the ban" refers to any line of conduct condemned by custom or public opinion.
In its earlier and general sense as a proclamation, the ban may be said to have been suspended by the writ. The word, however, survives in the sense of a proclamation in the "banns of marriage" (q.v.).
The Persian word ban, meaning lord or master, was brought into Europe by the Avars. It was long used in many parts of south-eastern Europe, especially in southern Hungary, to denote the governors of military districts called banats, and is almost equivalent to the German margrave. After enjoying very extensive powers the bans were gradually reduced, both in numbers and importance. Since 1868, however, the governor of Croatia and Slavonia has been known as the ban of Croatia, Slavonia and Dalmatia, but his duties are civil and not military. He is appointed by the emperor of Austria, as king of Hungary, and has a seat in the upper house of the Hungarian parliament.
See Du Cange, Glossarium, tome i. (Niort, 1883); H. Brunner, Grundzuge der deutschen Rechtsgeschichte (Leipzig, 1901); E. P. Boutaric, Institutions militaires de la France (Paris, 1863); Père G. Daniel, Histoire de la milice française (Paris, 1721).