In 1121 the Count of Holland dedicated a chapel on this spot to Saint Peter and Saint Paul. Leiden’s first church, named after St. Peter, has been extended over the centuries. The keys that Peter carried as keep of the heavenly gates can also be seen in Leiden’s coat of arms.

Until 1512 there was a 100-metre tower on the west side of the church,where there is now an open square. One night in that year, the tower suddenly collapsed, and was never rebuilt. The broken bells were melted down to make one large bell that was hung in a separate bellhouse. Building and maintaining a church is always an expensive business. To assist with the costs, in the first half of the 17th century, more than 30 houses were built onto the side of the church for rental.