The exact location, time and method of the entry of chess into western Europe is unknown, however linguistic evidence suggest that it was almost certainly obtained from the Arabs.
However the earliest western evidence of chess is dated to the eleventh century at the very earliest, still a signifcant time after the arabs themselves had discovered chess. Given that prior to eleventh century the arabs had substantial settlements in Spain, France and Italy knowing that our version of chess came from the arabs has not helped in identifying the entry point.
Philogical evidence points to an earlier date than archeological and literary evidence currently suggests, indicating that the game entered Europe perhaps as early as 900 AD.
HJR Murray, A History of Chess, (Oxford University Press)
Helena M. Gamer, The Earliest Evidence of Chess in Western Literature: The Einsiedeln Verses, Speculum, Vol. 29, No. 4. (October 1954), pp. 734-750.