The Crusader state of the Kingdom of Jerusalem, created in 1099, was divided into a number of smaller seigneuries.
According to the 13th century jurist John of Ibelin, the four highest "barons" (crown vassals) in the kingdom proper were :
This fourfold division, which did not cover a number of lordships, may be an artificial creation of the 13th century, as the power of various barons fluctuated enormously during the height of the kingdom in the 12th century.
There were also a number of independent seigneuries, and some land held under direct royal control, such as Jerusalem itself, Acre and Tyre.
Sidon appears to have been rather small, whereas Galilee covered a disproportionate number of sub-vassals and Sidon was located between Galilee's holdings.
Aside from the Kingdom of Jerusalem, there were also three other major Crusader states on the mainland:
These states nominally bore some dependency on the kingdom of Jerusalem. The King of Jerusalem was bound to reconcile them in case of disputes, or between a vassal Prince and the Latin Patriarich of Antioch, and could claim the regency in case of a vacancy or minority in their successions.
Edessa was perhaps the most closely tied to the Kingdom, despite its distance. Its first two Counts became kings of Jerusalem, and the county was bestowed as a royal gift on Joscelin I.
The County of Tripoli, the nearest of them, is sometimes considered to have been a vassal lordship under the king's suzerainty, although it preserved an extraordinary degree of sovereignty.
Antioch was almost independent, for it was founded already before the kingship and its first holder was a rival of kings, the original leader of the crusade. Later in its history, it would at times recognize Byzantine or Armenian suzerainty, or none at all.
These states dated their documents by the reigns of their own rulers, carried out their own foreign policy, and sent military aid to the Kingdom of their own will, rather than through feudal obligation; therefore, they are generally recognized as sovereign and are treated more fully under their own articles.