In 1673, 19 years old, he accompanied Marchese del Monte, the Emissary of Queen Christina, to Italy and Rome, where the royal protection ensured he would get the best teachers available; leading architects of the era such as Carlo Fontana and Gian Lorenzo Bernini. These architects, together with the compulsory study of classical monuments, made a lasting impression on Tessin. Upon his return to Sweden after four years, the Swedish king immediately sent him on a second trip which would last 1677-78 and take him to England and France were prominent architects such as André Le Nôtre and Jean Bérain had a deep impact on Tessin's later decorations and gardens. In 1687-88 he traveled to Rome and back to Sweden through Austria and Germany. During the trip he made extensive notes in a diary describing works of architecture he saw during the journey. Together with his stepbrother Abraham Winands, Tessin actively took part in his father's work, and when Tessin inherited his father's position, he asked to share it with Winands and the two would keep working side by side until the death of Winands in 1709.
