A fortified church is a church that is built to play a defensive role in times of war. Such churches were specially designed to incorporate military features, such as thick walls, battlements and embrasures. Others, such as the Cathedral of Ávila were incorporated into the town wall. Monastic communities, such as Lérins Abbey, are often surrounded by a wall, and some churches, such as St Arbogast in Muttenz, Switzerland, have an outer wall as well. Churches with additional external defences such as curtain walls and wall towers are often referred to more specifically as fortress churches or Kirchenburgen (literally "church castles").
A high concentration of fortified churches may be found in parts of Europe where there was a lot of hand-to-hand warfare, for example in the Dordogne region of France, which was fought over by France and England in medieval times, and in Transylvania, which was the scene of Ottoman invasions. Fortified churches were also built in places controlled by colonial empires, such as the one in the Philippines that served as the scene of the Siege of Baler.
Although a large number of fortified churches in a variety of styles existed in the lands of Belarus only a handful have survived until the present. The most famous include Christian Orthodox churches in Muravanka and Synkovichi, as well as Catholic fortified churches in Kamai and Ishkold'. In addition to Christian churches Belarus also has the ruins of several fortified synagogues, of which the Chief Synagogue in Bykhaw is most notable.