Scotland is a traditionally Christian nation in which, in the 2011 census, some 54% of the population said they were Christian, a significant fall from the 64% who said they were Christian in 2001. The Church of Scotland, or The Kirk, has legal recognition as the national church in Scotland: but, unlike the Church of England south of the border, it is not an "established church", i.e. it is not formally linked with the state.
The 2011 census asked those living in Scotland to state their religious affiliations. 32% said "Church of Scotland" (compared with 42% in 2001); 37% said "no religion" (compared with 27% in 2001); 16% said "Roman Catholic" (no change since 2001); 1.4% said "Islam" (compared with 0.8% in 2001); and around 0.1% said each of "Buddhism", "Sikhism", "Judaism", and "Hinduism".
In practice, a visitor to Scotland could leave without really having noticed the religious life of the country, were it not for the sometimes surprisingly large number of relatively modern churches, especially from the 1800s, in even quite small communities, many now converted for other uses; and for the ruins of once grand medieval abbeys, cathedrals or churches which form the basis of many of Scotland's visitor attractions. The exception to this is in the Western Isles. In the northern, Presbyterian, half of the chain of islands, Sunday Observance is strong, to the point where a visit including a stay over a Saturday or Sunday night needs careful planning. Meanwhile, in the southern, predominantly Catholic, half of the Western Isles, the presence of roadside shrines is highly reminiscent of southern European countries.
The story of the development of religion in Scotland is a complex one. Little or nothing is known about religious practices before the arrival in Scotland of Christianity, though it is usually assumed that the Picts practiced some form of "Celtic polytheism", a vague blend of druidism, paganism and other sects. Christianity may have started to have some impact in the Pictish world even before they pushed the Romans back from Hadrian's Wall in AD 367, but its first documented arrival in Scotland was in AD 397, when St Ninian founded the first Christian Church in Scotland at Whithorn. He then set to work converting the southern and eastern Picts to Christianity.
There were still Picts and Scots in need of conversion when St Columba arrived on the scene in the years after 563, and it seems likely that Celtic Christianity was firmly established across what is now Scotland by the end of the 600s. The next few hundred years were marked by the emergence of doctrinal differences between the Celtic Church and the Roman Church, and, from 795, the increasing presence in Scotland of initially pagan Vikings, first as raiders, then as settlers.
It was due to the influence of St Margaret, who married Malcolm III in 1070, that the Roman Church gained supremacy over the Celtic Church across Scotland. The main strand of the story of religion in Scotland over the following 500 years was one of the growing wealth and prestige of the Roman Church, an age in which numerous magnificent abbeys, priories, nunneries, collegiate churches and other churches were built across much of Scotland.
During the middle ages Scotland showed - by contemporary European standards at least - considerable religious tolerance. It was one of the few states in Europe not to systematically persecute Jews, and in the Declaration of Arbroath of 6 April 1320, the great and the good of Scotland put their name to a document containing the statement cum non sit Pondus nec distinccio Judei et Greci, Scoti aut Anglici, which translates as "there is neither bias nor difference between Jew or Greek, Scot or English".
500 years of Roman Catholicism, and any semblance of religious tolerance, came to a juddering halt with the Reformation in 1560. In Scotland this took the form of an orgy of destruction driven by an especially radical brand of Presbyterian Protestantism ("Presbyterian" means governed by representative committees rather than by a hierarchy of bishops). It led to the supplanting of the Roman Catholic Church in Scotland by the Presbyterian Kirk; and to the loss of much of the magnificent architecture built during the previous 500 years.
If the practice of religion in Scotland in the 1500s was destructive, things only got worse in the 1600s. First, efforts by James VI/I to secure his hold on Ireland resulted in his "Plantation of Ulster" in the early years of the century. Large numbers of Protestants from Scotland were offered land in return for settling in predominantly Catholic Ireland. Many took up the offer. This was to trigger an era of conflict in Ireland that has only very recently reached any sort of resolution.
In 1637, efforts by Charles I to impose an Anglican form of Protestantism in Scotland resulted in riots in Edinburgh. They were followed by a national uprising and the signing of the National Covenant by those who wished to retain a Presbyterian form of Protestantism in Scotland. This led directly to war with England over whether bishops should be introduced into the Kirk, which in turn led to the two English Civil Wars, to the occupation by Cromwell of Scotland, and, later in the century, to the "Killing Time", a period in which many Scots were killed because of their support for either the Covenant and radical Presbyterianism on the one hand, or the Crown on the other.
The lines of conflict changed when, in 1689, the English Parliament engineered the "Glorious Revolution" in which the Catholic James VII/II was displaced by his Protestant daughter Mary and her husband William of Orange. The Jacobite uprisings in Scotland in 1689, 1715, 1718 and 1745 all involved largely Catholic Highland clans supporting the Jacobites against the largely Protestant Hanoverians, who in turn received large scale support from Protestant Scots.
The 1800s saw two main developments on the religious front. The first was a series of schisms and splits that saw significant fragmentation within the established Protestant Kirk. Some of these were late healed, though not before they led to the building of large numbers of new churches in many communities across Scotland. The second was significant immigration by Irish Catholics to, particularly, west central Scotland. The Catholic communities here were later boosted by the arrival of Italians and Poles.
Since 1900 Scotland has seen the gradual decline in the numbers of those actively practicing the religions they were born into. But the period also saw significant levels of sectarianism, especially, but not exclusively, in west central Scotland. This was given particular expression in the relationships between the supporters of Glasgow's two dominant football teams, Celtic and Rangers: and, to a lesser degree, between those of Edinburgh's two football teams, Heart of Midlothian and Hibernians. Sectarianism, especially in relation to football, remains one of the least attractive aspects of modern Scotland. And to bring the picture completely up to date, the events of the last few years and their treatment in the media have given rise to a number of instances of religious intolerance of Muslims.
All in all, the story of the evolution of religion in Scotland does us little credit as a nation. Perhaps that is one of the reasons why, in 2011, Scotland's second biggest religion, and by far its fastest growing religion, was no religion at all.