JunD

Under the early Caliphates, jund (Arabic: جند‎‎; plural ajnad, اجناد) was a term for a military division, which became applied to Arab military colonies in the conquered lands and, most notably, to the provinces into which Greater Syria (the Levant) was divided. The term later acquired various meanings throughout the Muslim world.

The term jund is of Iranian origin, and appears in the Quran to designate an armed troop. Under the Umayyad Caliphate it came to be applied in a more technical sense to "military settlements and districts in which were quartered Arab soldiers who could be mobilized for seasonal campaigns or for more protracted expeditions" as well as the "corresponding army corps" (Dominique Sourdel).

Gradually, however, and aside from its technical use for the provinces of Syria (see below), the term acquired a broader meaning of the entire armed forces of a state. Thus one of the caliphal fiscal departments, the diwan al-jund, administered the pay and provisions of the army. In addition, the geographers of the 9th–10th centuries used the term ajnad as an equivalent of amṣar or large towns.

The most notable use of the term was in Syria, where already the Rashidun Caliph Abu Bakr is credited with dividing the region into four ajnad: Hims (Jund Hims), Damascus (Jund Dimashq), Jordan (Jund al-Urdunn), and Palestine (Jund Filastin). The Umayyad Caliph Yazid I then added the district of Qinnasrin (Jund Qinnasrin). This practice remained unique to Syria and was not emulated in any other province of the Caliphates, which were usually headed by a single governor; hence they were often referred to collectively as al-Shamat, "the Syrias".

...
Wikipedia