Historically swaddling bands were used for clothing when baptizing an infant. As time progressed full immersion of an infant was required for baptism. As a result christening clothing evolved since a baby needed to be unclothed and then clothed again when being baptized. When full immersion was discontinued another change in christening gowns took place that was influenced by not needing to unclothe an infant during baptism. Also, the styles and fashion of the day had a an influence on what christening clothing looked like.
Infant baptism is first mentioned around A.D. 160 to about 220 (How Old Is Infant Baptism. Piper, John). During this time period it was likely the clothing that infants wore when they were baptized were swaddling bands. Swaddling bands are "long strips of cloth wrapped all around the baby" (What on Earth are Swaddling Clothes. Welch, John W.). The purpose of wrapping a baby with swaddling is to restrict the baby's limbs from movement. The earliest depiction of swaddling bands have been found in tombs that are 4,000 to 4,500 year old in Crete and Cyprus. In these tombs there are votive statuettes displaying babies in swaddling bands (Swaddling, Wikipedia).
The most well known mention of swaddling bands is at Jesus' birth when in Luke 2:7 it states, "And she brought forth her first born son, and wrapped him in swaddling clothes." It was customary at the time that Jesus' swaddling bands were the same bands that were used at Mary and Joseph's wedding ceremony. During a wedding ceremony of the time period "under the wedding canopy, these decorated bands would be tied around the clasped right hands of the bride and groom; hence the saying, ‘they tied the knot’ (Welch).
These bands also could have had important symbols embroidered on them such as a lion, a lamb, or a tree of life, which represents the tribe of Judah. The colors blue and white may have been used as well as they are royal colors and Mary would have had the right to use those colors being a descendent of David (Welch).
By the time of the 16th century (1500s) we know for sure that swaddling bands were in use for ceremonies and christenings. One of the oldest examples of swaddling bands that are still in existence is found in the UK and dates back to around 1575 - 1600 (Buckingham Vintage. Buckingham Vintage in Antique & Vintage Clothes).
Full Immersion Baptism
Clothing for infant baptism began to change around the 17th century (1600s) due to the fact that infants were now required to be totally immersed in holy water. Because infants were being immersed it was important to be able to unclothe infants for baptism and then replace the clothes quickly over swaddling bands so the infant would not get cold. Removing christening clothes and replacing them quickly were important since churches of the time were not heated and could be very cold in the dead of winter. (Buckingham Vintage. Buckingham Vintage in Antique & Vintage Clothes and Mathiassen, Nosch, Toftegaard. Fashionable Encounters: Perspective and Trends in Textile and Dress in the Early Modern Nordic World).
By the time of the 18th century (1700s) baptism practices had changed from full immersion to not having to immerse an infant. This ended the practice of having to undress an infant for baptism. Also, by this time it was viewed that swaddling bands were unhealthy for babies and as a result their use ceased. As a result of these two things, christening clothing began to change to look more like the more traditional victorian christening gowns we are familiar with today. These gowns were made of silk or satin. Babies would wear petticoats underneath these gowns. (Buckingham Vintage. Buckingham Vintage in Antique & Vintage Clothes).
In the 19th century (1800s) Christening gowns were modeled after women's fashion of the day with a high short bodice, low scooped boat neck adjustable with drawstrings and a high gathered waist also adjustable with drawstrings.These types of dresses were designed to be worn over petticoats. This style of gown was a unisex style that had a V shaped yoke bodice and an inverted V front panel falling from the yoke to the hem. For boys the pointed tip of the bodice could be pointed out and tucked in for girls.
When the 20th century (1900s) arrived white linen or cotton christening gowns began to grow in popularity. It was covered in broderie anglaise lace and floral embroidery. It had short frill sleeves made from lace, a V shaped bodice and an inverted V front panel.
In the 21st century the traditional victorian christening gown is seeing a resurgence in popularity. Mainly because of the christening of Prince George (Buckingham Vintage. Buckingham Vintage in Antique & Vintage Clothes)
*Sourced material is cited in the body of the article.