Fischer von erlach major contribution to vienna was the karlskirche a building that reflects his view that every work should be unique.by borrowing from a wide range of historical sources, he created a highly original desing that referred to many major buildings of the past. the church was dedicated to st. charles borromeo, the emperor's patron saint, and was built in fulfillment of a vow charles VI made in 1713 during an outbreak of the plague. its broad facade is dominated by a dome on a drum rising above a pedimented portico, flanked by columns in a manner recalling the front of s. agnese in agone, where the central dome is flanked by twin campaniles. elements from historical buildings