Mitford was promoted to captain and in September 1940, during the Italian invasion of Egypt, led his LRDG patrol from Cairo deep into Libya on their first reconnaissance mission. The patrol crossed the Libyan Desert to the Jalo oasis and Kufra. It raided two enemy emergency landing grounds, destroying unguarded aircraft and a considerable amount of aviation spirit and a supply convoy carrying petrol and official mail. The effectiveness of this first patrol was reflected by the Italians having to reduce their front line forces, and reinforce the troops garrisoning the area, from 2,900 men to 5,500 by November 1940.