[1] Lyon’s father had been MP for Forfar in 1734 which was subsequently held by William Maule.
After an exhausting struggle Panmure was returned for the Forfar and Lyon for Aberdeen Burghs.
As a result, the Strathmore and Panmure families made an agreement to avoid future contests.
He succeeded his mother to the Hetton-le-Hole estate in Durham on 22 April 1778 and vacated his seat at the opening of the autumn session of 1778.
[2] Lyon and his son John believed there was good coal under the Hetton estate and carried out prospecting from the 1770s.