Nidan (sometimes known as Midan or Idan) was a Welsh priest and, according to some sources, a bishop, in the 6th and 7th centuries. He is now commemorated as a saint. He was the confessor for the monastery headed by St Seiriol at Penmon, and established a church at what is now known as Llanidan, which are both places on the Welsh island of Anglesey. He is the patron saint of two churches in Anglesey: St Nidan's Church, Llanidan, built in the 19th century, and its medieval predecessor, the Old Church of St Nidan, Llanidan. Midmar Old Kirk in Aberdeenshire, Scotland, is also dedicated to him: Nidan is said to have helped to establish Christianity in that area as a companion of St Kentigern. St Nidan's, Llanidan, has a reliquary dating from the 14th or 16th century, which is said to house his