20thcentury arab arabcountries biographies biography civilization contributionsinsociologyibnkhaldūn earlyworksto1800 empireislamique historians historiography history ibnkhaldun ibnkhaldūn ibnkhaldūn inprocess islamicarchitecture islamiccivilization islamicempire islamiclearningandscholarship mlcmn2001/00329(d) philosophy politicalandsocialviews politicalandsocialviewsibnkhaldūn politicalsociology savants scholars socialsciences sociology to1500 travel travelibnkhaldūn ʻabdal-raḥmānibnmuḥammad ابنخلدون،