We know King James I of England primarily through his name being attached to the King James Version of the Holy Bible, which was printed in 1611. Before he was James I of England, he was James VI of Scotland, enthroned there in 1567. He was a Protestant King, but also believed in the divine right of kings to rule, which often brought him into conflict with his Scottish subjects.
What Did the Scottish Reformation Accomplish by 1567?

By 1567 the Scottish Reformation had succeeded in taking over the churches in Scotland, pushing out the Roman Catholic Church and obtaining all its property. The Church of Scotland was also legally free from civil influence, and had a more localized organization, able to appoint its own leaders and pastors in local districts called presbyteries. Most of the trappings of Roman Catholicism were cast out, and the Church of Scotland had a heavy Calvinistic influence.
The Church of England was different. While it too had separated from the Roman Catholic Church under Henry VIII, much of its structure was still Catholic in nature, with the crown having the authority to appoint bishops and handle church matters.
What Did King James Do?

James VI was technically crowned King of Scotland when he was only 13 months old, after his mother, Mary, Queen of Scots, was forced to abdicate. He did not fully come into his full power until 1583 when he was sixteen years old. He extensively believed in the divine right of kings, where he was given full power by God to rule, and pushed the Scottish Parliament to pass the Black Acts in 1584. The Black Acts were a series of laws which gave James VI power over the Church of Scotland similar to that which the English throne had over the Church of England.
Presbyteries, were done away with and bishops directly appointed by the king were placed in charge. James VI also prevented the General Assembly – the meeting of the heads of the Church of Scotland- from meeting until he could control its process and implement practices closer to the Church of England under the Five Articles of Perth.
What Were the Five Articles of Perth?

The Five Articles of Perth were James VI’s attempt to impose some structures and practices of the Church of England onto the Church of Scotland. They included kneeling during communion, private baptism, private communion for those who were sick, children catechized and blessed by a bishop, and celebrating certain religious holidays like Christmas and Easter.
Many of the objections to the Five Articles of Perth and similar measures were that it made the church appear more Catholic. Many of the Scottish reformers had rejected, sometimes violently, the Roman Catholic Church, and had gone so far as to tear out all the decorations and discard all the ceremonial tools Catholic Churches used. Sunday was considered the only “Holy” day, and the rejection of Roman Catholicism was so pervasive that even holidays celebrated by Protestants today, Christmas and Easter, were discarded by Scottish protestants.

When the Articles were passed, King James wrote a letter to the leadership, stating that:
“The sword is now putt into your hands; goe on therefore to use it; and let it roust noe longer till ye have perfited the service trusted to you, or otherwise we must use it both against you and them. If anie or all of you be faint- hearted we are able enough (thanks to God) to put others in your places who both can and will make things possible which ye think so difficult.”
As well as:
“But as Papistrie is ane disease in the minds, so is Puritaisme in the braine. So the onlie remedie and antidote against it will be a grave, settled, uniforme, and well-ordered church, obedient to God and their King, …”
Over the next few decades following King James VI’s push against the Scottish Protestants would be a large back-and-forth struggle between the Church of Scotland and its King, which also held the throne of England.