The Twelve Days of Christmas was written to help preserve the traditions of the catholic faith during the years that catholicism was banned in England. The song is steeped in symbolism and the fact that it is so well known throughout the world is a testament to the faith of the followers of the catholic doctrine. The symbols contained in the song are as follows:

1st verse    "1 "True Love" refers to God.
2nd verse   "2 Turtle Doves" refers to the Old and New Testaments.
3rd verse   "3 French Hens" refers to Faith, Hope, and Charity.
4th verse    "4 Calling Birds" refers to the Four Gospels or the Four Evangelists.
5th verse    "5 Golden Rings" refers to the first five Books of the Old Testament.
6th verse    "6 Geese-a-laying" refers to the six days of creation.
7th verse    "7 Swans-a-swimming" refers to the seven sacraments.
8th verse    "8 Maids-a-milking" refers to the eight beatitudes.
9th verse    "9 Ladies dancing" refers to the nine fruits of the Holy Spirit.
10th verse  "10 Lords-a-leaping" refers to the Ten Commandments.
11th verse  "11 Pipers piping" refers to the eleven faithful apostles.
12th verse  "12 Drummers drumming" refers to the twelve points of the Apostle’s creed.

It is very interesting, that a song we all know so well, could contain so many hidden meaning. I would never have guessed that it was anything more than lovely Christmas carol. It’s always nice to learn something new, especially about the wonderful celebration of Christmas. 

I hope you learned something, too. 
Merry Christmas to all!