'Douglas I' was an Allied special forces operation to parachute a three-man British and French 'Jedburgh' team into the Morbihan area of German-occupied France to establish liaison with the local resistance forces (6 August 1944 onward).

'Douglas I' may be taken as a typical 'Jedburgh' undertaking. At 22.00 on 5 August the 'Douglas I' party (the British Captain R. A. Rubinstein and Sergeant J. D. Ravden, and the French Lieutenant J. Roblot), accompanied by Second Lieutenant J. Poignot of the Forces Françaises de l’Intérieure, took off in a Short Stirling four-engined aeroplane from the RAF base at Fairford in Gloucestershire. Rubinstein was wearing a British paratrooper’s uniform, armed with a 0.45-in (11.4-mm) Colt pistol and 0.3-in (7.62-mm) M1 carbine with folding stock, a commando knife, and 5 million francs for local purchases and wages for the French resistance forces. The aeroplane could not find the dropping zone, however, and returned to Fairford. This was perhaps lucky, for the party’s supplies had not reached Fairford in time to accompany the party was were therefore to have been dropped to them at a later time. On the following day, the party travelled to Keevil, and from here lifted into the air in a pair of Stirling aircraft at 23.15 with two Stirlings. The party was dropped successfully with all nine of its supply packages, landing in Brittany just to the north-east of Vannes at the SAS’s 'Dingson' base area together with 17 French reinforcements for the SAS group. The task was to operate with the local resistance forces in their effort to cut off the German naval bases and their garrisons of the area, and in particular Lorient, from all possibility of their movement toward the Allied 'Overlord' lodgement in Normandy.

The dropped personnel and their supplies were met by 150 members of the local population, of all ages and both sexes, and then escorted to a site on which a camp had been established for them.

To get to the headquarters of the local resistance unit, the 'Douglas I' team was to travel by truck and boat, but as there was room for only six supply packages, two remained hidden at the drop zone, the ninth having been lost. Security was not good, and on the day after the drop one of the female resistance personnel was arrested by the Germans. Hiding in woods, the 'Douglas I' party went to collect the supply packages and arrived only 10 minutes after the departure of a German search party which had found nothing. From the woods and away from prying civilian eyes, the party made its first radio contact with London at 07.15 on 7 August, and during the night of 7/8 August was relocated to the safety of local FFI headquarters at the home of a M. Tristan, the député for Morhiban, and the 5 million francs were handed over. The party was moved on 8 August to a small oyster farm, where the men remained for a week, sending many messages to London but making only poor contact with the 'Aloes' mission. On 16 August, the 'Douglas I' party moved to the headquarters of the FFI in Vannes, and made contact with the US Army.

In his later report, Rubinstein complained of poor responses from London to requests for supply deliveries to the SAS and FFI, which lowered his standing with the locals.

Most of the Brittany countryside was empty of the the Germans by this time, but the Germans were still present in strength in the port areas, and it was here that the Germans had to be contained and harassed. The 'Douglas I' party also assisted the SAS with the landing of several gliders carrying arms for 3,000 men, and later Douglas Dakota transport aircraft with additional supplies. By a time late in August the party’s job was done. Rubinstein believed that his team had in fact arrived too late to be of real use to the FFI and that much of the information about local German strength was already known to the Americans. The 'Douglas I' party was extracted by Dakota to Normandy and thence by another aeroplane, which was also carrying wounded troops, to Hendon outside London on 24 August.