The following introduces an official guide of the Collegiate Church of St Peter in Westminster as revised in 1988 and reprinted in 1994.

For close on twelve hundred years - perhaps for longer - it is believed that a religious community has existed in the area we think of today as 'Westminster Abbey' and its precincts.
Over the centuries the constitution of 'the Abbey' has changed several times, and within each major period of its history there have been gradual alterations in the life and activities of those who visit the Church of Westminster or work for the Abbey in one capacity or another. The degree to which we can state this with confidence depends mainly on two factors: the distance in time and the survival of historical, architectural or archaeological evidence. For the earliest periods, until the Norman Conquest, the remoteness in time and the almost total lack of records combine together, so that very little can be said of the abbey's history. But our knowledge of Westminster from the twelfth century until 1540, during which time it was a Benedictine Abbey, and from 1560 until today, is very detailed. Only in the two periods of religious and political disturbance (in the middle years of the sixteenth and seventeenth centuries) is the evidence scanty, although not entirely wanting.
Nevertheless, continuity there has been. Divine service has been celebrated within the walls of the Abbey Church on its present site for nine hundred years, and Westminster School, which had its origin in the monastic school, remained even when the Chapter had been expelled during the Commonwealth. There are other centuries-old links; the Benedictine tradition of welcome to visitors; the Coronation Church of all the crowned sovereigns of England since William I in 1066, perhaps since Harold II (in the same year); the burial place of royalty, of the great in peace and war, of the lesser men and women who have served the Abbey, of those who have been benefactors or who simply have lived near by.
But while these separate traditions have been carried on changes have been and are made: the very building of the Abbey Church and precincts has been transformed; the uses made of its component parts have been altered. Great assemblies of Church and State were held within precinct walls; in the now-ruined Chapel of St Catherine in the monastic Infirmary bishops were consecrated; the Commons met in the monks' Chapter House or in their Refectory; when, after the dissolution of the Monastery, the Chapter House no longer had its old function, it was used as a repository for State records; the great room where the monks had slept was turned part into a Library and part into a School-room; the ancient Granary, in what is now Dean's Yard, became a dormitory for the Westminster Scholars; the lodgings and offices of the Monastery were adapted as houses for the Dean and Canons and others. Some of the buildings remain almost intact or easily recognizable; some exist although partly altered inside and out; some have gone altogether.
The Church and the Great Cloister almost certainly have changed he least, and it is probably safe to say that the exterior of the Abbey Church today would be easily recognized by anyone familiar with it in the last days of the Monastery. Inside, however, although the general plan is essentially the same, the wall-surfaces have been transformed. We know the dedications of many of the medieval altars in the Church , but today there are only eleven altars. The Chapels of St Andrew, St Michael, St John the Evangelist, Our Lady of the Pew, St John the Baptist, St Paul, St Nicholas, St Edmund, and St Benedict are chapels only in name, and the places where their altars stood are occupied by tombs or memorials. These changes resulting from the Reformation have given the Abbey one of the features for which it is most celebrated: the place of burial and of commemoration of the great and famous. But it is a mistake to think that, for an individual to have a monument or grave in the Abbey Church or Cloisters, he or she must be greatly distinguished. From early times a person connected with the Abbey, either as Abbot or a senior monk, might be included; during the Middle Ages laymen and women of comparative obscurity could be buried within the walls of the Church. From the sixteenth century, when more monuments were added and records of the epitaphs are known, and from 1607 when the Burial Register begins, we know the names of many more. It was common practice then for College servants and members of their families to be buried in the Cloisters, together with some of the clergy, and not unknown for some laymen who held Abbey offices to have graves in the Church.
The presence of a particular monument in the Abbey, or why (at any one time) an individual was buried here, is more a comment on the social, political, and cultural history of that age. The memorials themselves can be studied in many ways and all can be found to have interest or merit. An idea prevails now that some writer, some statesman deserves the honour of at least an Abbey memorial if not actual burial; it is as if Poets' Corner or the Musicians' or Scientists' Aisle is incomplete without such an addition. By the eighteenth century this notion was apparent: Milton (d. 1674), excluded for years on political grounds, was accorded a memorial in 1737, and, perhaps the most surprisingly belated of all, Shakespear (d. 1616) not until 1740. The inclusion of Nelson's wax effigy among those of persons who actually were buried in the Abbey was because those whose perquisites of office included 'the Tomb Money' were annoyed at the knowledge of the crowds flocking to the Admiral's grave at St Paul's, but, in Nelson's words, 'Victory, or Westminster Abbey', he expected for himself an Abbey monument or grave.

O/S Co-ords:3006.7949
Source(s):

Westminster Abbey - Official Guide