While out hunting, young James was seized by men led by Boyd,
and he was taken to Edinburgh where Sir Robert assumed command of
the entire Realm, with the initial support of the Queen
Mother. This resulted in Boyd becoming the enemy of many
Scottish nobles who he had previously made bonds with, including
Darnley, Montgomery and Hamilton. These actions also made a victim
out of his brother Sir Alexander. In support of Sir Robert, Sir
Alexander broke all of his bonds. However, soon after Sir Robert's
rise to power he rejected his brother and relieved him of his
custody of Edinburgh Castle.
Nevertheless, Sir Robert did take part in some wise governmental
arrangements. During his regency, Denmark pawned the Orkney and
Shetland islands to Scotland in lieu of a royal dowry for his
daughter Margaret's marriage to James III in 1469. Yet, in the eyes
of the Scottish nobility, he was an upstart, and suspicions rose
high about his motives due to his quickness to shirk bonds and to
repudiate his own brother. Misgivings grew further when Boyd
embarked on a policy of aggrandisement for himself and those close
to him, including his son Thomas, who was created Earl of Arran and
married to the King's sister, Princess Mary.
With the Boyds now in a position where they could inherit the
throne, the nobility as well as the young King grew restless and
were prompted to rise against the Regency of Sir Robert. In the
Summer of 1469, Sir Robert, his son Thomas, and his brother Sir
Alexander were left to face charges of treason for the kidnap of
the King and misgovernance thereafter. Sir Robert and Sir Thomas
escaped execution by fleeing to the continent. Only Sir Alexander
was left to face the charges, and for his brother's ambition he was
beheaded at Castle Hill before the decade was out.