After serving as a junior officer defending the Bank of England during the Gordon Riots he took part in the Flanders Campaign including the retreat into Germany during the French Revolutionary Wars.

[1] Grosvenor served as a brigade commander at the Battle of Copenhagen in August 1807 for which he was rewarded with promotion to lieutenant-general on 25 April 1808.

[2] In January 1810, he spoke in Parliament in support of Lord Porchester's demands for an inquiry into the disastrous expedition that had taken place the previous year and with which Grosvenor had been so closely associated.

[7] In 1820 he had a fortunate escape during the Cato Street Conspiracy when an angry mob overturned his carriage into the River Dee.

[2] He was promoted to field marshal on 9 November 1846[11] and died at his home, Mount Ararat at Richmond Hill on 20 June 1851.