[1] Richard served under York in French military service, fighting at the sieges of Mouzon in 1653 and Landrecies in 1655.
[2] After the English Restoration, Bertie returned to England and was admitted to the Middle Temple, but did not pursue legal studies.
[1] At the outbreak of the Monmouth Rebellion in June 1685, Bertie served as captain of an independent troop of horse.
His half-brother Charles remarked that Richard's old commander York, now King James II, "calls my brother Dick his old fellow-soldier, and intends him more than a troop".
[1] However, both Richard and his younger half-brother Captain Henry Bertie lost their commissions in December 1685 for failing to support the King's program of installing Roman Catholic army officers.