The tradition of marking the start of Lent has been documented for centuries. Ælfric of Eynsham's "Ecclesiastical Institutes" from around 1000 AD states: "In the week immediately before Lent everyone shall go to his confessor and confess his deeds and the confessor shall so shrive him as he then may hear by his deeds what he is to do [in the way of penance]". By the time of the late Middle Ages, the celebration of Shrovetide lasted until the start of Lent. Pancakes are commonly eaten on this day. Since foods such as butter, eggs and fat are discouraged from being eaten during the Lenten season, Christians use these ingredients during Shrovetide to make pancakes or other rich foods, such as fasnachts and pączkis. The specific custom of Christians eating pancakes on Shrove Tuesday dates to the 16th century. Along with its emphasis on feasting, another theme of Shrove Tuesday involves Christians repenting of their sins in preparation to begin the season of Lent in the Christian calendar. In many Christian parish churches, both Protestant and Roman Catholic, a popular Shrove Tuesday tradition is the ringing of the church bells (on this day, the toll is known as the Shriving Bell) "to call the faithful to confession before the solemn season of Lent" and for people to "begin frying their pancakes".