2008 sees the 850th anniversary of the death of St Rognvald, the Viking Earl who founded St Magnus Cathedral. Riders of Sea Horses celebrates Rognvald's pilgrimage to the Holy Land, a story of swashbuckling adventure, romance and intrigue. Children from nine Orkney schools, with the support of choreographer Ali Gunn, visual artist Sarah MacLean and their teachers, have devised a spectacular commemoration, culminating in a ceremony depicting the foundation and building of Orkney's magnificent Cathedral.