Peter then set off on the so-called "Wandering Years" (), the Medieval German tradition of working as a travelling craftsman after completing apprenticeship. On these visits he learned the most important concepts of Gothic construction techniques in Central Europe. He visited Cologne, perhaps Paris, and certainly spent time in Strasbourg – precise knowledge of Strasbourg Cathedral can be seen in his subsequent buildings. While working in Cologne he met Druda (Gertrud), daughter of the resident architect Bartholomäus von Hamm. They eventually married and had four children: three sons, of which two went on to become known master builders in their own right, and a daughter.