The oldest document concerning the relic of the Holy Blood in Bruges dates back to 1256.

Thus, between 1150 and 1256 there is a gap of a century ! Could it be that the relic arrived in Bruges later than 1150 ?

Probably, because at that time there was a relic of the Holy Blood in Constantinople, namely in the Maria Chapel of the imperial palace of Bucoleon.

This relic belonged to a whole series of relics connected with the suffering of Christ.

In 1203 Constantinople fell into the hands of the crusaders. The imperial city was sacked during the 4th crusade (1204).

Baldwin IX, Count of Flanders, was chosen as the new emperor.

Presumably he sent looted relics to Flanders and particularly to Bruges. His daughters Johanna and Margaretha were in charge of the county. It is likely that this is the way Bruges came into possession of the relic of the Holy Blood. Also the manner in which the rock-crystal flask is cut indicates an origin in Constantinople.