James V died at Falkland Palace on 14 December  1542.
Beaton tried to become one of the regents for the infant sovereign Mary, Queen of Scots.
He based his claim on an alleged will of the late King; but the will was generally regarded as forged, and The 2nd Earl of Arran, heir presumptive to the throne, was declared regent.
A copy of the alleged will was preserved by  Regent Arran.
Dated 14 December 1542 in the King's bedchamber at Falkland Palace, it was witnessed by James Learmonth of Dairsie, Master Household; Henry Kemp of Thomastoun, Gentleman of the Chamber; Michael Durham, the King's doctor; John Tennent, William Kirkcaldy of Grange, Master Michael Dysart, Preceptor of St Anthony's at Leith; John Jordan, Rector of Yetham; Francis Aikman, perfumerer, and others at the bedside.
 However, the clerk who wrote the instrument, Henry Balfour, a canon of Dunkeld, was not a recognised notary.

By order of the Regent, Beaton was committed to the custody of Lord Seton, and imprisoned at Dalkeith Palace and then Blackness Castle.
A papal interdict followed the arrest of the Cardinal Primate, according to which all churches of the country should be closed and administering the sacraments should be suspended.

With Beaton out of power, the Anglophile party persuaded Regent Arran to make a marriage treaty with England on behalf of the infant Queen, and to appoint a number of Protestant preachers.
The treaties signed at Greenwich in July 1543 stipulated that Mary would be accompanied by an English nobleman/gentleman (and his wife) until she was ten years old and afterwards would reside in England until the time of her marriage.
The union of the thrones of England and Scotland which the treaty envisaged was controversial from the start.
Its Anglo-centric policy was resisted by many who preferred to continue the Auld Alliance with France.
Resistance to the treaty resulted in a surge in the popularity of the French faction and the release of Beaton from prison.
The Treaty of Greenwich was rejected by the Scottish Parliament on 11 December 1543, leading to eight years of Anglo-Scottish conflict known as the Rough Wooing.
In 1543 Beaton regained power, having earlier drawn up the Secret Bond.
Two English invasions followed - and for these many blamed Beaton.

In December 1545 Beaton arranged for the arrest, trial and execution of Protestant preacher George Wishart, who on 28 March 1546 was strangled and afterwards burned.
Wishart had many sympathisers, and this led to the assassination of the Cardinal soon afterwards.
James V died at Falkland Palace on 14 December  1542. Beaton tried to become one of the regents for the infant sovereign Mary, Queen of Scots. He based his claim on an alleged will of the late King; but the will was generally regarded as forged, and The 2nd Earl of Arran, heir presumptive to the throne, was declared regent. A copy of the alleged will was preserved by  Regent Arran. Dated 14 December 1542 in the King's bedchamber at Falkland Palace, it was witnessed by James Learmonth of Dairsie, Master Household; Henry Kemp of Thomastoun, Gentleman of the Chamber; Michael Durham, the King's doctor; John Tennent, William Kirkcaldy of Grange, Master Michael Dysart, Preceptor of St Anthony's at Leith; John Jordan, Rector of Yetham; Francis Aikman, perfumerer, and others at the bedside.  However, the clerk who wrote the instrument, Henry Balfour, a canon of Dunkeld, was not a recognised notary.
By order of the Regent, Beaton was committed to the custody of Lord Seton, and imprisoned at Dalkeith Palace and then Blackness Castle. A papal interdict followed the arrest of the Cardinal Primate, according to which all churches of the country should be closed and administering the sacraments should be suspended.
With Beaton out of power, the Anglophile party persuaded Regent Arran to make a marriage treaty with England on behalf of the infant Queen, and to appoint a number of Protestant preachers. The treaties signed at Greenwich in July 1543 stipulated that Mary would be accompanied by an English nobleman/gentleman (and his wife) until she was ten years old and afterwards would reside in England until the time of her marriage. The union of the thrones of England and Scotland which the treaty envisaged was controversial from the start. Its Anglo-centric policy was resisted by many who preferred to continue the Auld Alliance with France. Resistance to the treaty resulted in a surge in the popularity of the French faction and the release of Beaton from prison. The Treaty of Greenwich was rejected by the Scottish Parliament on 11 December 1543, leading to eight years of Anglo-Scottish conflict known as the Rough Wooing. In 1543 Beaton regained power, having earlier drawn up the Secret Bond. Two English invasions followed - and for these many blamed Beaton.
In December 1545 Beaton arranged for the arrest, trial and execution of Protestant preacher George Wishart, who on 28 March 1546 was strangled and afterwards burned. Wishart had many sympathisers, and this led to the assassination of the Cardinal soon afterwards.
David Beaton