Exceptional climate of tolerance
The attic church was commissioned by the affluent Catholic merchant Jan Hartman and was put into use in 1663. During the time when Hartman and his family resided in the canal house, Amsterdam was under the rule of a Protestant city government. It was prohibited to practice the Catholic faith in public.
Former Catholic churches and monasteries were confiscated and repurposed for Protestant worship. Catholics had to seek alternatives and celebrate their mass in concealed home churches. This was tolerated by the city government! The Dutch Republic operated on the principle of freedom of conscience.
Behind closed doors, everyone was free to think and believe as they wished. This created an exceptionally tolerant climate for the time, allowing various religious communities to coexist in the city.