As early as the 1950s, the Bundesbahn was considering operating express trains with speeds of more than 160 km/h. Initially, a derivative of the E 10 standard locomotive or the pre-war E 19 locomotive was under discussion as locomotives for such trains. Finally, there was an invitation to tender for a six-axle locomotive with an output of at least 5,000 kW, which should be able to pull express trains at up to 200 km/h and heavy express trains at 160 km/h.
Henschel was awarded the contract and in 1965 delivered four pre-series machines as the E 03, which had already demonstrated their performance during the International Transport Exhibition. Despite many defects due to immature technology, they showed for the first time that scheduled express trains are possible at 200 km/h. Before the transition to series production, the requirements were further increased, so that 480 tonnes had to be towed at 200 km/h and 800 tonnes at 160 km/h. In 1970, series production of a total of 145 examples of the DB flagship, now known as the class 1031, began.
With a continuous output of 7,440 kW, they were the most powerful one-piece locomotives in the world and remain the most powerful locomotives built in Germany to this day. For a short time it was possible to call up an output of 10,400 kW or even 12,000 kW by switching the transformer, which is far above the output of today's three-phase locomotives. However, this was soon limited to 9,000 kW in favor of the service life of the components. At 9,800 kW, the short-term maximum output of the electric brakes on the 103 is also significantly higher than that of modern locomotives.
To facilitate maintenance, the locomotive body was divided into segments for the first time, which could be removed individually and thus allowed access to the interior of the engine room. Another innovation was the automatic driving and braking control, which is also used today for trips under LZB. The diamond-shaped pantographs that were initially installed were later replaced by a single-arm design, as they occasionally caused damage to the overhead lines.
For many years, the 103 remained the flagship of the Bundesbahn and served trains such as the Intercity or TEE. The class 120 three-phase locomotive, which was introduced in small numbers in the 1980s, could not compete with it because of its lower output. The first 103s only started to be phased out in 1997, since many locomotives were already very worn out from years of high-strain use. They were thus replaced by the new 101 and ended their regular service in 2003. Today, the last surviving locomotives are occasionally used as brake locomotives, as their high power makes them ideal for this.