Tradition says that the first church in this place was built on the ruins of a pagan temple from the 10th century, but the present church was built at the end of the 15th century, by the effort of the then owner of the town, the Płock cathedral canon and local priest Jan Sierpski. It was established in a market settlement dating back to the early 11th-12th century and one of the oldest castellany in Mazovia. It was expanded at the beginning of the 16th century by a southern chapel and renovated by voivode and the starost of Płock, Andrzej Sieprski in 1569. It was destroyed by fires in 1630 and 1648, and transformed in 1776, when a sacristy with a treasury and a crypt were added. After the fire of 1794, it was rebuilt only in 1844. At that time, a south porch was built, and the treasury adjacent to the north wall of the chancel was demolished. During World War II the church was converted into a grain store. In the 50s of the 20th century it was thoroughly renovated after the war.
It is a gothic church, orientated, made of brick with erratic stones and millstones in the lower floors of the tower. It consists of one nave with a narrower chancel closed straight from east and a massive, four-storey, square tower. At the beginning of the 16th century, the chapel of the Holy Cross was added to the southern wall of the nave and already in the 18th century the northern sacristy. The tower was decorated with irregularly arranged windows and plastered blendes and supported with two buttresses. In its ground floor a vestibule was placed, opened by ogival arcade to the nave.
Kunkel R.M., Architektura gotycka na Mazowszu, Warszawa 2005.
Website wikipedia.org, Kościół św. Wita, Modesta i Krescencji w Sierpcu.