This is the clearest lesson in Bruges on what is medieval and what is Victorian, and you get it by climbing one staircase.
The lower chapel of St Basil is Romanesque, usually dated to about 1134–1157 and built for Thierry of Alsace, count of Flanders. Visit Bruges describes it as the only Romanesque church building in West Flanders that has survived almost complete. It is dark, low, undecorated, roofed with stone rib-vaulting on heavy round pillars, and it holds a 12th-century relief of the Baptism of Christ. Nothing here is trying to impress you, which is precisely why it is the most convincingly medieval interior in the city centre.
Go up the Steegheere staircase — the bluestone front is a reconstruction, in a style caught between late Gothic and early Renaissance — and the upper chapel is a different world: painted, gilded, stencilled, crowded with statuary and stained glass. The shell is 15th-century Gothic. Almost all of the decoration is late-19th-century neo-Gothic, and Visit Bruges says as much. Neither chapel is a fake, but only one of them looks the way it looked to a Burgundian. Stand at the top of the stairs and compare.
The relic of the Holy Blood is a phial of cloth said to be stained with the blood of Christ. The tradition is that crusaders brought it to Bruges — the count Thierry of Alsace, returning from the Second Crusade, is the name usually attached. Visit Bruges words it carefully as “said to have been brought to Bruges by the crusaders”, and the documentary record of the relic in Bruges begins about a century later than the tradition claims, so treat the 1150 story as a story. What is not in doubt is that the town organised itself around this object for 700 years, and still does: the relic is brought out every day for veneration from 14:00 to 16:00, and on Fridays also from 10:15 to 11:00, and you can join the short queue and see it at arm’s length for nothing.
The adjoining treasury costs €5 and holds the Great Shrine of the Holy Blood, made by the Bruges silversmith Jan Crabbe in 1614 — the reliquary carried through the streets on Ascension Day. The church was raised to the rank of basilica in 1923.
One date to know: the Procession of the Holy Blood takes over the whole city on Ascension Day, and the basilica’s own site gives the next as Thursday 6 May 2027. On that day the relic is not in the building.