That original chapel had been built in 1347 as a result of the miracle of Amsterdam (15 March 1345), located on the Kalverstraat where this miracle with the eucharistic host occurred.
This miracle was officially recognised by the Roman Catholic Church, and a large pilgrimage chapel, the Heilige Stede ("Holy Site") was built where the house had stood, and the Heiligeweg ("Holy Way") as a pilgrimage route to it.