On February 12, 1941, a fleet of ships crossed the Mediterranean Sea from Italy to bring a German panzer division to the aid of the Italian army fighting against the British in Libya. Under the command of General Erwin Rommel, the 15th Panzer Division brought with them a newly developed light German tank specifically designed for desert warfare. In the initial skirmishes, the British learned that this light desert-perfect German tank was vastly superior to anything they had. The number of tanks the German army brought over was a military secret, but the analysts on the British side knew that the factories that produced those tanks had given them a consecutive sequence of serial numbers. Statistical techniques were used to determine the number of tanks in the German Africa Corps on the basis of serial numbers of captured tanks.