Rogation Days, the Monday, Tuesday, and Wednesday preceding Ascension Day, on which special litanies are sung or recited by the Roman Catholic clergy and people in public procession; has its origin in an old custom dating from the 6th century. In England the practice ceased after the Reformation.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Roeskilde * Roger I.