He was commissioned by Louis XV to lead two ships of French reinforcements for the 1745 Jacobite rising, landing at Stonehaven in October 1745 with soldiers for the army of Prince Charles, the Young Pretender.
In gratitude for the news, and for the safe delivery of several prisoners captured at the battle, the French court awarded him the rank of colonel, and he was made a knight of the Order of Saint Louis.
[1] Following the Jacobite defeat at the Battle of Culloden in April 1746, Warren volunteered to lead the mission to rescue Prince Charles from Scotland.
Departing from Saint-Malo on 31 August with two French ships, Le Prince de Conti and L’Heureux, he landed at Loch nan Uamh in the Sound of Arisaig on 6 September.
On 3 November 1746 James Francis Edward Stuart made Warren a baronet in the Jacobite peerage for "gallant service"; however he was only allowed to use this title publicly after 1751.