The Basilica of the Holy Blood is a relatively modest-sized church on Bruge's second most important square - the Burg. Hidden away in the corner, it is split into two very distinct chapels one located above the other.
It originated as a small church adjacent to the Oud Steen where Flemish royalty used to live. At some point between 1150 and 1256, the relic of the Holy Blood arrived in Bruges following the ransacking of the Maria Chapel within the palace of Bucoleon in Constantinople (modern-day Istanbul) by the crusaders as part of 4th crusade. The new Constantinople emperor Baldwin IX was of Flemish origin and thus sent a number of treasures back to his daughters Johanna and Margaretha who ruled from Bruges at the time.
The lower chapel is a fine example of Romanesque architecture. The decoration is minimal, colours dark and the tone rather modest compared to latter church buildings. This room is particularly small and can feel very cool even in warm weather.
The upper chapel also started its life during the same period in the 11th-12th century, but was significantly rebuilt in the 15th and 19th centuries in a classical gothic style. The decoration is noticeably more rich with deep crimson colours and a bright gold-covered altar.
The relic of the Holy Blood is kept by the order of the Basilica and is showcased annually during the Procession of the Holy Blood attended by tens of thousands of pilgrims from all over the world. The relic comprises of a phial with a piece of cloth stained with Jesus' blood preserved by Joseph of Arimathea. Scientific study has concluded that the phial was indeed made in or near Istanbul in the 10-12th century adding a lot of weight to the religious claims.