"vassalage" is a correct and usable word in written English.
It refers to the relationship between a vassal and a lord or ruler, in which the vassal agrees to provide services or resources in exchange for protection. For example, "The vassalage system of feudal Europe ensured that noble families were able to protect their holdings from attack."
Nevertheless, vassalage of sorts and customs of chivalry and knighthood developed.
The Reconquista was nearly completed by the middle of the 13th century, by which time the Muslims retained only the small kingdom of Granada (Arabic: Gharnāṭah) in vassalage to Castile until 1492.
When, in 1063, his uncle died without issue, Alp-Arslan became sole heir to all the possessions of the dynasty except Kerman, in southern Iran, which was held by one of his brothers, whom he promptly reduced to vassalage.
These two ill-advised adventures were designed to bring China under Hideyoshi's sway and to provide an outlet for tens of thousands of warlike samurai only recently and loosely brought under Hideyoshi's vassalage.
Eastern Georgia was reduced to vassalage under the Mongol Il-Khanid dynasty of the line of Hülegü, while Imereti, as the land to the west of the Suram range was called, remained independent under a separate line of Bagratid rulers.
The war was renewed, however, and Charles was captured at La Roche-Derrien in January 1347 and incarcerated in the Tower of London; he paid a ransom and promised to hold Brittany, under vassalage to Edward.
While endemic private warfare, brigandage, and problems associated with vassalage and inheritance still existed, some monarchies were already developing better-integrated systems of government.
In 1246 Muḥammad I secured the recognition of Ferdinand III of Castile (his neighbour on all landed frontiers) in return for a vassalage which, though often ignored, remained in force until the kingdom's disappearance in 1492.
A later attempt to throw off the vassalage brought another Delhi army; Ramachandra was imprisoned but was later released and remained loyal to Delhi until his death.
To strengthen his control over the population, Charlemagne attempted to develop intermediary bodies; he tried to use both vassalage and immunity as means of government in the first instance by creating royal vassals and giving them public offices and in the second by controlling protected institutions such as monasteries and the Jewish community.
In 1062 he forced the Muslim ruler of Toledo to pay him tribute and imposed vassalage on Saragossa and Sevilla.
