BL MS Harley 2977, a surviving Rituale of the Abbey of Bury St Edmunds, offers a glimpse of the ceremonies for St Edmund's Day and other high points of the year in the abbey church (thread)
The procession for the mass of St Edmund began in the cloister, before descending to the crypt, coming up into the ambulatory around the presbytery (where the shrine of St Edmund stood), and then pausing beneath the great rood before passing into the nave packed with pilgrims
A monk with an aspergilium headed the procession, sprinkling holy water, followed by two crucifers, two acolytes and monks bearing the feretrum of St Edmund (the bier on which Edmund's coffin was transported in 1010 and 1013)
Behind the feretrum, chaplains in richly embroidered copes bore the holiest relic of all - the camisia, a shirt stained with St Edmund's blood when he was martyred by the Danes. Since the shrine itself was never opened, this was the closest the faithful would come to the saint
A succession of subdeacons and deacons then bore more relics in procession, including the arm of St Botolph, the abbey's principal relic of Suffolk's second greatest saint
Finally, as incense billowed from the brass censers of acolytes, the Lord Abbot himself brought up the rear of the procession in a splendid cope of cloth of gold, wearing the mitre and carrying his crozier
Lengthy processions like these were characteristic of the Sarum Rite. The English were known throughout Europe for their love of processions! This was why even large secular churches started building cloisters in order to accommodate processions...