What is "gunthertuch"

The so-called ( ‘Gunther's shroud’) is a Byzantine silk tapestry which represents the triumphal return of a Byzantine Emperor from a victorious campaign. The piece was purchased, or possibly received as a gift, by Gunther von Bamberg, Bishop of Bamberg, during his 1064–65 pilgrimage to the Holy Land. Gunther died on his return journey, and was buried with it in the Bamberg Cathedral. The fabric was rediscovered in 1830, and is now exhibited in the Bamberg Diocesan Museum.