The evening before the day of the Consecration itself, in keeping with tradition, a vigil service was held. The Relics of St. Clement and St. Severus, contained in a small leaden box together with a scroll attesting to their validity were placed in a magnificent wooden casket made by one of our parishioners. Psalms and canticles relating to these two martyrs were sung. The relics of St. Clement are thought to be those of the first century Pope, fourth in succession as the Bishop of Rome after St. Peter. Unfortunately, it is uncertain to which St. Severus in the Christian martyrology the relics of St. Severus belong.
The use of relics in the Christian tradition can be traced back to the very early Church. In the account of the martyrdom, written by Marcion, of St. Polycarp in about 156 and presumably following an already established practice, we read that following his burning at the stake, that; "So, after all, we did gather up his bones - more precious to us than jewels, and finer than pure gold and we laid them to rest in a spot suitable for the purpose. There we shall assemble, as occasion allows, with glad rejoycings; and with the Lords permission we shall celebrate the birthday of his martyrdom." In Rome at about this time, the cult of the relics of martyrs was associated with services being held at or on their tombs. The Doctors of the early Church seem to have had no difficulty in accepting this practice or the importance of relics in Christian worship, with the provision that their role should be kept in the proper perspective. St Jerome (c.341-420) writes; "We do not worship, we do not adore, for fear that we should bow down to the creature rather than to the Creator, but we venerate the relics of the martyrs in order the better to adore Him whose martyrs they are".
By the fourth century, although when this practice first began is uncertain, there seems to have been a change in the practice in the handling of the relics of martyrs. Previously, the remains seem to have been kept intact; however, by this time and presumably because of the spread of the Christian Faith, we find, as in the case of the body of St. Stephen discovered in 415, relics being divided and despatched to different parts if the Christian world. St. Gregory of Nyssa (c. 330-c.395) writes; "...their ashes and all that the fire had spared have been so distributed throughout the world that almost every province has had its share of the blessing. I also myself have a portion of this holy gift and have laid the bodies of my parents beside the ashes of these warriors, that in the hour of the resurrection they may be awakened together with these highly privileged comrades." This practice seems not to have been approved by Rome herself and the prohibition was repeated by Pope St.Gregory the Great (c.540-604), late in the sixth century.
The use of relics as an integral part of a consecrated church was formalised by the Second Council of Nicea. Called in 787 in response to the Iconoclastic Controversy, it ordered that no church should be consecrated without them.
The relics themselves have something of an interesting history. Originally placed in the high altar of St. Chads Cathedral in Birmingham in 1848 just prior to the time of the restoration of the Catholic Hierarchy in England and Wales by the Vicar-Apostolic (later Cardinal) Nicholas Wiseman, they remained there through various changed for over a century until a refurbishment of the Cathedral in the mid-1990s. During this, the relics were removed and the altar then in use, was acquired by the Parish and came to the Church of the Immaculate Conception in Bicester the relics came with it.
During the Consecration service itself, the wooden casket containing the relics, which had remained at the Sanctuary steps throughout the night and the following day, was ceremonially carried around the church, shoulder high, by two deacons accompanied by four torch-barers with two cantors (one of whom was Fr. Aldo) following, whilst the Litany of the Saints was chanted. The procession stopped at the Sanctuary steps while the deacons with the casket approached His Grace. The relics were then removed, placed and sealed into the cavity in the mensa.
Sources:
The Catholic Encyclopaedia
E.A.Livingstone The Concise Dictionary of the Christian Church
Michael Walsh A Dictionary of Devotions
David Hugh Farmer The Oxford Dictionary of Saints
J.N.D.Kelly The Oxford Dictionary of Popes
Maxwell Staniforth Early Christian Writings
Chambers Biographical Dictionary
The evening before the day of the Consecration itself, in keeping with tradition, a vigil service was held. The Relics of St. Clement and St. Severus, contained in a small leaden box together with a scroll attesting to their validity were placed in a magnificent wooden casket made by one of our parishioners. Psalms and canticles relating to these two martyrs were sung. The relics of St. Clement are thought to be those of the first century Pope, fourth in succession as the Bishop of Rome after St. Peter. Unfortunately, it is uncertain to which St. Severus in the Christian martyrology the relics of St. Severus belong. 
