The surplice originally reached to the feet, but as early as the 13th century it began to shorten, though as late as the 15th century it still fell to the middle of the shin, and only in the 17th and 18th centuries did it become considerably shorter. In several localities it underwent more drastic modifications in the course of time, which led to the appearance of various subsidiary forms alongside the original type. For example:
The surplice belongs to the vestes sacrae, though it requires no benediction. All clericss may wear it, even those who have only received the tonsure, the bishop himself vesting with it those whom he has newly tonsured. It has very varied use in divine service. It is worn in choir at the solemn offices; it forms the official sacral dress of the lower clergy in their liturgical functions; the priest wears it when administering the sacraments, undertaking benedictions, and the like -- the use of the alb being nowadays almost exclusively confined to the mass and functions connected with this. In general such use, in all main particulars, became the custom as early as the 14th century.
Lack of exact information obscures the older history of the surplice. Its name derives, as Durandus and Gerland also affirm, from the fact that its wearers formerly put it on over the fur garments formerly worn in church and at divine service as a protection against the cold. Some scholars trace the use of the surplice at least as far back as the 5th century, citing the evidence of the garments worn by the two clerics in attendance on Bishop Maximian represented in the mosaics of S. Vitale at Ravenna; in this case, however, confusing the dalmatic with the surplice. In all probability the surplice forms no more than an expansion of the ordinary liturgical alb, due to the necessity for wearing it over thick furs. The first documents to mention the surplice date from the 11th century: a canon of the synod of Coyaca in Spain (1050); and an ordinance of King Edward the Confessor. Rome knew the surplice at least as early as the 12th century. It probably originated outside Rome, and was imported thence into the Roman use. Originally only a choir vestment and peculiar to lower clergy, it gradually - certainly no later than the 13th century — replaced the alb as the vestment proper to the administering of the sacraments and other sacerdotal functions.
The Oriental rites lack a surplice and any analogous vestment. Of the non-Roman Catholic Churches in the West the surplice has continued in regular use only in the Lutheran churches of Denmark, Norway and Sweden, and in the Church of England.
Church of England
The second Anglican Prayer Book, that of Edward VI in 1549, prescribed the surplice as, with the tippet or the academical hood, the sole vestment of the minister of the church at "all times of their ministration", the rochet being practically regarded as the episcopal surplice. The more extreme Reformers furiously assailed its use, but in spite of their efforts, Elizabeth's Act of Uniformity (1559) retained the garment, and the advertisements and injunctions issued under her authority enforced its use, though they ordered the destruction of the "massing vestments" - chasubles, albs, stoles and the like.
The surplice has since remained, with the exception of the cope, the sole vestment authorised by law for the ministers, other than bishops, of the Church of England (for the question of the vestments prescribed by the "Ornaments Rubric" see vestment). And apart from clerks in holy orders, all the "ministers" (including vicars-choral and choristers) of cathedral and collegiate churches, as well as the fellows and scholars of colleges in chapel have worn surplices since the Reformation. The clergy (at least its more dignified members) have employed as a distinctive mark the tippet or scarf above mentioned, a broad band of black silk worn stole-wise, but not to be confused with the stole, since it has no liturgical significance and originally formed a mere part of the clerical outdoor dress. Formerly the clergy only wore the surplice when conducting the service, and exchanged it during the sermon for the "black gown", i.e. either a Geneva gown or the gown of an academical degree. This custom has, however, as a result of the High Church movement, become almost completely obsolete. The "black gown", considered wrongly as the ensign of Low Church views, survives in comparatively few of even evangelical churches; however, preachers of university sermons retained the custom of wearing the gown of their degree.
The traditional form of the surplice in the Church of England survived from pre-Reformation times, viz: a wide-sleeved, very full, plain, white linen tunic, pleated from the yoke, and reaching almost, or quite, to the feet. Towards the end of the 17th century, when large wigs came into fashion, it became convenient to have surplices constructed gown-wise, open down the front and buttoned at the neck, a fashion which still partially survives, notably at the universities. In general, however, the tendency followed continental influence, and curtailed the surplice's proportions. The ample vestment with beautiful falling folds has thus in many churches given place to a scanty, unpleated garment scarce reaching to the knee. In the more "extreme" churches the surplices frankly imitate the Roman cotta.
Original text from the 1911 Encyclopaedia Britannica.