SPONSOR, one who stands surety for another (from Lat. spondere, to promise), especially in the rite of Christian baptism, a godfather or godmother. The practice originated not in infant baptism, but in the custom of requiring an adult pagan who offered himself for the rite to be accompanied by a Christian known to the bishop, who could vouch for the applicant and undertake his supervision, thus fulfilling the function performed in the Eleusi nian mysteries by the mystagogus. The Greek word for the per son undertaking this function is Itvaboxos, to which the Latin susceptor is equivalent. The word "sponsor" in this ecclesiastical sense occurs for the first time, but incidentally only, and as if it were already long familiar, in Tertullian's treatise De baptismo (ch. 18), where, arguing that in certain circumstances baptism may conveniently be postponed, especially in the case of little children, he asks, "For why is it necessary that the sponsors like wise should be thrust into danger, who both themselves by reason of mortality may fail to fulfil their promises, and may also be disappointed by the development of an evil disposition [in those for whom they become sponsors] ?" The sponsors here alluded to may have been in many cases the actual parents, and even in the 5th century it was not felt to be in appropriate that they should be so ; Augustine, indeed, in one pas sage appears to speak of it as a matter of course that parents should bring their children and answer for them "tanquam fide jussores" (Epist. . . . ad Bonif. 98), and the oldest Egyptian ritual bears similar testimony. Elsewhere Augustine contem plates the bringing of the children of slaves by their masters, and of course orphans and foundlings were brought by other benevolent persons.
The comparatively early appearance, however, of such names as compatres, commatres, propatres, promatres, patrini, matrinae, is of itself sufficient evidence, not only that the sponsorial relation ship had come to be regarded as a very close one, but also that it was not usually assumed by the natural parents. How very close it was held to be is shown by the Justinian prohibition of marriage between godparents and godchildren. On the other hand, the anciently allowable practice of parents becoming sponsors for their own children, though gradually becoming obsolete, seems to have lingered until the 9th century, when it was at last formally prohib ited by the council of Mainz (813). For a long time there was no fixed rule as to the necessary or allowable number of sponsors and sometimes the number actually assumed was large. By the council of Trent, however, it was decided that one only, or at most two, these not being of the same sex, should be permitted.
The rubric of the Church of England, that "there shall be for every male child to be baptized two godfathers and one godmother, and for every female one godfather and two god mothers," is not older than 1661; the sponsors are charged with the duty of instructing the child, and in due time presenting it for confirmation. In the Roman Catholic Church the spiritual relationship established between the sponsor and the baptized, and the sponsors and the parents of the baptized, constitutes an impediment to marriage. (See MARRIAGE; CANON LAW.)