With Poland's conversion to Christianity in the late 10th century, the pagan "stanice" were probably Christianized by replacing pagan symbols with Christian ones such as images of patron saints, or a Chi-Rho or dove symbolizing the Holy Spirit. In the year 1000, during his pilgrimage to the tomb of Saint Adalbert in Gniezno, the capital of Poland until about 1040, Emperor Otto III officially recognized Duke Boleslaus the Brave as King of Poland (see Congress of Gniezno), crowning him and presenting him with a replica of the Holy Lance, also known as Saint Maurice's Spear. This relic, together with the "vexillum" attached to it, was probably the first insignia of the nascent Kingdom of Poland, a symbol of King Boleslaus's rule, and of his allegiance to the Emperor. It remains unknown what images, if any, were painted or embroidered on the "vexillum".