Truscott took command of the 3rd Infantry Division in March 1943, and oversaw preparations for the Allied invasion of Sicily, codenamed Operation Husky. He was known as a very tough trainer, bringing the 3rd Infantry Division up to a very high standard. At the age of 48, he was one of the youngest division commanders in the U.S. Army at the time. He led the division in the assault on Sicily in July 1943, coming under the command of the Seventh U.S. Army, commanded by Patton, now a lieutenant general. Here his training paid off when the division covered great distances in the mountainous terrain at high speed. The famous 'Truscott Trot' was a marching pace of five miles per hour over the first mile, thereafter four miles per hour, much faster than the usual standard of 2.5 miles per hour. The 3rd Infantry Division was considered to be the best-trained, best-led division in the Seventh Army.