North Herts has a rich history of medieval churches - dating as far back as the 12th century.

St Mary's Church in Ashwell was built in 1381, and features medieval graffiti showing St Paul's Cathedral and highlighting the plight of victims of the Black Death.

Royston Crow: The old St Paul's Cathedral carved into the wall in St Mary's Church, AshwellThe old St Paul's Cathedral carved into the wall in St Mary's Church, Ashwell (Image: North Herts Museum)

Meanwhile in Letchworth, the Church of St Mary - which was built in the late 12th century - features graffiti of a medieval ship.

Royston Crow: A medieval picture of a ship in the Church of St Mary's, LetchworthA medieval picture of a ship in the Church of St Mary's, Letchworth (Image: North Herts Museum)

Medieval churches were painted inside, so graffiti was scratched onto painted walls which made it stand out. Church authorities seem to have approved of the graffiti - which often had a religious theme, with crosses a common feature.

Royston Crow: A human figure in a shroud in St Lawrence's Church, NewnhamA human figure in a shroud in St Lawrence's Church, Newnham (Image: North Herts Museum)

After the reformation, the insides were usually whitewashed to cover up earlier decoration, in particular depictions of heaven and hell. From that point onwards graffiti was usually not religious, and people would carve their initials, dates and other pictures or messages.

Royston Crow: Graffiti of a knight at St Mary's Church in WallingtonGraffiti of a knight at St Mary's Church in Wallington (Image: North Herts Museum)