William Mackenzie, 5th Earl of Seaforth
(died 1740) was a Scottish nobleman.
He who joined the Jacobite
standard at Braemar
, during the rising of 1715
, and then, having raised 3000 men, was present at the battle of Sheriffmuir
and was appointed lieutenant-general of the northern counties. He escaped to France in 1716.
He accompanied George Keith, 10th Earl Marischal
in his expedition to the Highlands, being wounded at Glenshiel
. He again escaped to France, returning to Scotland only in 1726 after he was pardoned.
In 1716 he was attainted
and his titles and estates forfeited. Before his death in January 1740, he had been relieved of some of the penalties of his treason
, although his titles were not restored. His son Kenneth Mackenzie, Lord Fortrose
(c. 1718–1761), who but for the attainder would have been the 6th earl, helped the British government during the rising of 1745
, and was a member of parliament
for some years.
His son Kenneth Mackenzie
was created Earl of Seaforth in 1771, but his peerage became extinct when he died in August 1781. Although there were still heirs to the older earldom, this remained under attainder. Kenneth raised the regiment of Highlanders, the 78th
, known later as the 2nd battalion of the Seaforth Highlanders