Today we know that Scotland is a Presbyterian country. From what I heard they officially adopted Presbyterianism in 1560 as part of what is known as the Scottish Reformation.
However before Protestant ideas spread in Scotland was it a predominantly Catholic country? I ask this because I have heard of the Celtic Church and wonder if it continued to survive. Did this church survive or was it assimilated into the Catholic Church?
Furthermore, did the Scottish church have any special arrangements such as a special relationship with Rome, different doctrines, practices, or was Scotland before the 16th century a more or less standard Catholic country, both in lowlands and highlands?
Scotland was a Roman Catholic country. But it was subject to near constant warfare, particularly the lowlands which were constantly being overrun by the British and the Highlanders who sought control. So it's people had a stubborn independent streak which probably made the Reformation more likely. Note that during the 16th and 17th centuries there were attempts by the British to make the Church of Scotland Episcopalian in government but these failed. There is a Scottish Episcopal Church which is part of the Anglican Communion but it is not the state church, for the Church of Scotland is Presbyterian. So when the Queen goes to Scotland she is technically a Presbyterian during that time. I believe that it was the leadership of the Scottish Episcopal Church who were the ones who sought union with the Orthodox in the early 18th century. They sought to be received under the Patriarch of Jerusalem but then plans fell apart. Do not forget the Catholic Stuarts, James II, the Old Pretender and Bonnie Prince Charlie, who sought to take the English throne with the support of France and the Roman Catholic Church. I think that a lot of their support came from Scotland.
It was the a group of Anglican Bishops who refused to violate their oath to King James II, in who was overthrown by the Glorious Revolution of 1688. Since James was a Stuart, the royal dynasty of Scotland, which assumed the English throne after the death of Queen Elizabeth I, who never married and had no heir, under James i in 1603. The Stuarts were anti-Cavinist because of their experiences with the Scotch Presbyterian Church. James I's son, Charles I was overthrow and executed in 1649 by the Puritans, extreme Calvinistic Protestants who felt that the Reformation had not gone far enough in England and demanded that the Church of England be purified of what they considered Catholic practices and adopt pure Calvinism. After the death of he leader of the Puritans, Oliver Cromwell who had established a theocracy enforcing Calvinism on the English people, a segment of the army overthrew Oliver Cromwell's son Richard, and restored the Stuart monarchy in the person of Charles II, the son of the executed Charles I. Charles II died in 1685, becoming a Roman Catholic on his death bed. Since Charles ii had no heir, James II his brother assumed the throne. However James II was openly sympathetic to Catholicism and was overthrow in 1688. At this point, James II's daughter, the wife of the Stadtholder (Governor) William of Orange of Holland and devout Protestant was placed on the throne.
Those English Bishops who refused to violate their oath to James II formed a schismatic church that had its strongest following among the Scottish Episcopalians. They were called Non-Jurors because thy refused to violate their oath to James II. The Non-Jurors were more Catholic oriented than other Anglicans and did seek union with Orthodoxy. However they sought union on their terms and were unwilling to embrace the Orthodox Faith without reservation and the negotiations ended in failure. Another reason for the failure was the protests of the British monarchy to the Tsar Peter II that the Non-Jurors were disloyal to the monarchy.
Fr. John W. Morris