On the accession of the latter to the throne, Andrew Stone was appointed treasurer to Queen Charlotte, and attaching himself to Lord Bute he became an influential member of the party known as "the king's friends," whose meetings were frequently held at his house.
He remained in office in 1761, when his brother Lord Temple and his brother-in-law Pitt resigned upon the question of the war with Spain, and in the administration of Lord Bute he was entrusted with the leadership of the House of Commons.
On the 25th of March 1761 Bute succeeded Lord Holderness as secretary of state for the northern department, and Pitt resigned in October on the refusal of the government to declare war against Spain.
In 1864 the Bute trustees unsuccessfully sought powers for constructing three additional docks to cost two millions sterling, but under the more limited powers granted in 1866, the Roath basin (12 acres) was opened in 1874, and (under a substituted act of 1882) the Roath dock (33 acres) was opened in 1887.
Excavations carried out by the marquess of Bute from 188 9 onward furnished for the first time conclusive proof that Cardiff had been a Roman station, and also revealed the sequence of changes which it had subsequently undergone.