The unveiling of a plaque at Lincoln Cathedral commemorates the blood libel of 1255, when 18 Lincoln Jews were hanged having been falsely accused of the ritual murder of a local boy.

Kaddish for the hanged Jews was also recited at a service at the shrine of Little Hugh, who was venerated as a saint. The wording on the plaque records that when the boy’s tomb was opened in 1791, the body bore no signs of mutilation.

The 200 people at the service were addressed by Liberal Judaism chief executive Rabbi Danny Rich on “A Jewish view of Jesus”.

“It was an incredible privilege to be at the service,” he said. “It is a tribute to the cathedral and to the local Jewish community that this type of event is now possible.” Lincoln Labour MP and Jewish community member Gillian Merron was another congregant.

Dean of Lincoln Reverend Philip Buckler said the plaque was “a symbol of changed attitudes and the rejection of false prejudice”.

On the same day, JTrails — part of Spiro Ark — launched a Jewish heritage trail of the cathedral area. JTrails’ director Marcus Roberts said it showed that “until prejudice took over in the 13th century, Lincoln Jews and Christians were able to learn from each other”.