Assertion: fortress's wall | /r/HasProperty | improved by arab
Facets:
Source sentences:
text: The current fortification and walls were built by the Persian Sassanian Empire as a defensive structure against hostile nomadic people in the north, and continuously repaired or improved by later Arab, Mongol, Timurid, Shirvan and Iranian kingdoms until the early course of the 19th century, as long as its military function lasted.