Bolesław I Chrobry
Otto III made a pilgrimage from Rome to Aachen and Gniezno (Gnesen), stopping at Regensburg, Meissen, Magdeburg, and Gniezno. The Congress of Gniezno (with Bolesław I Chrobry) was part of his pilgrimage. In Rome, he built the basilica of San Bartolomeo all'Isola, to host the relics of St. Bartholomew.