For the ever heavier passenger and freight trains on the Gotthard after World War II, the SBB needed more powerful electric locomotives. The requirements which resulted in the Ae 6/6 included an hourly output of 6,000 hp, a maximum weight of 120 tonnes and an effective dynamic brake. As basis for the development, SLM, BBC and Oerlikon used the CC 6051 delivered to the SNCF in 1950.

The Ae 6/6 had two three-axle bogies and was designed in a modular system that facilitated repairs. With a top speed of 125 km/h and a starting tractive effort of 392 kN, it was sufficient for all types of trains and could haul 600 tonne trains up the Gotthard with 75 km/h. It didn't have multiple controls, what was deemed unnecessary at this time due to their high power.

With their livery that included chrome lines and the coat of arms of Swiss cantons, the first 25 locomotives earned international popularity. The next 95 were christened after towns, but the founding of the new canton Jura led to an additional one being renamed in 1979. As early of 1969, No. 11414 was modified for high-speed service and was tested in Germany at speeds of more than 200 km/h.

When the four-axle Re 4/4 III and the much more powerful Re 6/6 were introduced on the Gotthard, the Ae 6/6 were sent to flatter regions. In the new scheme, they were soon renamed to Ae 610. Due to their top speed, they were only used in freight traffic since the nineties. After their retirement between 2002 and 2013, 13 have been preserved, of which six are still operational. Others had been earmarked for preservation either by SBB Historic or by private associations, but were not restored or were even scrapped.