Accompanied by jingling bells and sung in sweet harmony by a heavenly church choir, they are the very essence of a merry Christmas.

Love them or loathe them, Christmas carols are about to be unleashed across the land, providing the soundtrack to the festive period for weeks to come.

But while they may seem like relatively unprovocative tunes with flowery lyrics extolling the birth of a baby, bright stars and faithful pilgrims, it transpires some may be far more sinister.

Indeed, according to one scholar, some of the nation’s favourite Christmas carols appear to have their roots in rebellion, politics, protest and, in some cases, drunken partying and pagan frolics.

According to The Rev Professor Ian Bradley, Emeritus Professor of Cultural and Spiritual History, University of St Andrews, and editor of The Penguin Book of Carols, the charming Christmas ditty may be less innocent – or religious for that matter – than first thought.

“Carols have always had this anarchic cultural quality, and often would carrying a political message,” he says. “Because of their pagan background, until relatively recently, churches did not like having them at all.”

Carols only became a feature of church services in Scotland at the beginning of the 20th century, and not much earlier than in England.

While one of the most familiar carols is believed to have been a far more rebellious call to arms than it may at first seem.

“O Come All Ye Faith on the face of it seems to be a straightforward hymn of admiration for the new-born baby Jesus,” he adds. “But it was written as a coded message to rally Jacobites to the cause of Bonnie Prince Charlie on the eve of the 45 rebellion.”

It’s thought the carol was originally written in Latin by a strong supporter of the Jacobite cause, John Wade, who attended an English Catholic College in Douai, France.

A weekly Mass was held at the College where prayers were offered for the return of the Stuarts to the British throne.

It’s led researchers to suspect the carol’s call to “ye faithful” may have had a double meaning and was intended to rally Jacobite supporters. While a reference in the Latin version to “Regem angelorum”, meaning ‘king of the angels, may instead be an anti-Hanoverian message of opposition to King George II.

Dr Bradley says there is a string of indicators to suggest there is more to the carol than a celebration of the infant Jesus.

“The early manuscript mentions ‘our King James’ in Latin, which appears to be a reference to the Old Pretender, James Francis Edward Stuart, son of James VII.

“And there are Stuart cyphers and thistle decorations.

“Wade was a plain-chant scribe who had gone to France almost as an exile, where he copied manuscripts and taught Latin. As you might expect from an English Catholic college in exile, they did not have much time for Hanoverians.”

The song was sung only in Roman Catholic places of worship for decades, while carols – even those which praised Jesus and celebrated his birth – were shunned elsewhere.

“They were very much seen as rather vulgar and populist and did not come into the Church of England until 1850 and in Scotland until the end of the 19th century,” he adds.

“Instead, they were sung outside in the street, outside pubs and homes where the church did not have so much control.”

St Francis of Assisi – regarded as ‘the Father of Christmas Carols – is said to have inspired the birth of the Christmas carol in the 13th century after he created nativity scenes in a cave and invited people to sing and worship around a manger.

But while Franciscan friars brought songs praising the Christmas story from Italy, churches preferred hymns based strictly on the scriptures, and viewed carols as having Pagan connections, associated with fertility rituals.

“When we look at the earliest use of the word ‘carol’ in English language in the 1300s, it seems to be a round dance with singing associated with fertility, and no religious significance,” Prof. Bradley adds.

“Franciscan friars were bringing songs to the people here, they picked them up and would sing in streets, homes and pubs, but not in church.”

As carols became more popular, their role for delivering hidden messages grew, he adds.

“The Twelve Days of Christmas was possibly a Catholic song used to teach Catholic doctrine - the five gold rings are the five sacraments of the Catholic Church.

“This was possibly post-Reformation, and the song used to teach tenets of Catholic faith when they were forbidden to practise their faith.”

While another, Angels from the Realms of Glory, is believed to contain subversive messages from its author, James Montgomery, a Scots-born political radical who had been twice imprisoned for his support of the French Revolution and reform riots in Britain.

“The original last verse talked about justice repelling the sentence of those who had been in prison and mercy breaking the chains,” adds Dr Bradley.

Perhaps more in the spirit of Christmas, It Came Upon the Midnight Clear contains a message of peace and a call for an end to strife, written by Edmund Sears, a minister in Massachusetts with strong liberal views who wanted peace and social reform.

“He wrote it after there had been particularly bloody revolutions in Europe and a costly war between the United States and Mexico, and it contains the words ‘O hush the noise, ye men of strife, and hear the angels sing’,” adds Dr Bradley.

“It’s a fairly universal sentiment but tempered by his own political instinct.”

Prof. Bradley will reveal the secrets behind Christmas carols during a talk next Friday (DECEMBER 3) at Scotland’s first religious literary festival, organised by the School of Divinity at the University of Edinburgh.

The festival, part of celebrations to mark the 175th anniversary of New College, the home of the School of Divinity, features a programme of 25 events, including an exploration of the relationship between religion and crime writing in a presentation by crime author Val McDermid.

Best-selling author Robert Harris will discuss portrayals of power, religion and politics in his work, including Fatherland, Enigma and the Cicero trilogy.

Acclaimed author Charles Foster and broadcaster Sally Magnusson will also take part, while actor, comedian and writer, Miles Jupp will explore the complex connections between religion, comedy and literature.

The festival runs between December 3-5. Details can be found at the Winter Tales Festival website: