In the search for a heavy mixed traffic locomotive for lines in the north with a low axle load limit, the SJ introduced the EII in 1907. It had four driving axles and no carrying axles to get the maximum adhesive weight. The driver diameter of 1,388 mm allowed for a top speed of 65 km/h, what was enough for passenger trains in this region. Additionally, they were the first SJ locomotives with inside cylinders. Between 1907 and 1920, 130 were built for the SJ. One of these had received peat firing for trials.
Another company that ordered three of the same locomotives new in 1917 was the Kalmar nya järnvägsaktiebolag (KJ). In 1925 and 1926, the Ostkustbanan (OKB) bought 14 from the SJ. Also the Uddevalla–Vänersborg–Herrljunga Järnväg (UVHJ) and the Skåne-Smålands Järnväg (SSJ) bought one each in 1936 and 1937, respectively. All of these had re-joined the SJ by 1940 when all private railways had been nationalized.
As early as in 1935, the SJ had started to equip these locomotives with a leading axle. In this process, the boiler was also relocated for the right weight distribution and the top speed was increased to 70 km/h. Additionally, some locomotives got a larger four-axle bogie tender instead of the three-axle one. By 1951, a total of 90 had been rebuilt and renamed to E2.
After they had become too slow for passenger trains, they were only used in freight and shunting service on branch lines. All had been withdrawn from active service in 1972, but some were kept as reserves until 1990. Today more than 30 are still existing, with a few of them still operational.