On the night of 15 March 1345, in the house of a poor man named Ysbrand Dommer on the Kalverstraat in Amsterdam, a dying man was given the Last Rites and received Communion. Shortly afterward he vomited. Following the priest's customary instruction that nothing consecrated should be thrown out carelessly, the woman tending him gathered the matter, which contained the Sacred Host, and cast it into the hearth fire.
The next morning, raking the fire, she found the Host floating undamaged among the embers, entirely intact and untouched by the flame; her hand, reaching in to recover it, suffered no burn. The Host was placed in a casket and the parish priest of St. Nicholas (the Oude Kerk) was summoned. He carried it in solemn procession back to the church. Twice it was carried to the church; twice, by an account no one could explain, it returned of itself to the house on the Kalverstraat. The pastor declared a public miracle and asked Bishop Jan van Arkel of Utrecht to investigate.
The bishop approved the miracle in 1346. A chapel — the Heilige Stede ('Holy Site') — was built on the spot and the Host enshrined there; the annual public procession on 15 March became one of the great feasts of medieval Holland, drawing pilgrims from across northern Europe. Suppressed at the Reformation, the pilgrimage survived clandestinely — individuals walking the old route at night — and was revived in 1881 as the silent night-procession of laymen, the Stille Omgang, which still walks the original route through central Amsterdam in March each year and remains one of the largest surviving Eucharistic processions in the world. The Begijnhof chapel houses the memorial.