The name Commercial Road had been proposed for the original Aldgate East station, which opened on 6 October 1884 as part of an eastern extension to the Metropolitan District Railway (now the District Line), some 500 feet to the west of the current station, close to the Metropolitan Railway’s Aldgate station. However, when the curve to join the Metropolitan Railway from Liverpool Street was built, the curve had to be particularly sharp due to the presence of Aldgate East station, at which it needed to be straight.

As part of London Transport’s 1935-1940 New Works Programme, the triangular junction at Aldgate was enlarged, to allow for a much gentler curve and to ensure that trains held on any leg of the triangle did not foul the signals and points at other places. The new Aldgate East platforms were sited almost immediately to the east of their predecessors, with one exit facing west toward the original location, and another at the east end of the new platforms.

The new eastern exit was now close enough to the next station along the line, St Mary’s (Whitechapel Road), that this station could also be closed, reducing operational overhead and journey times, as the new Aldgate East had effectively replaced two earlier stations.

The new station, opened on 31 October 1938 (the earlier station closing permanently the previous night), was designed to be completely subterranean, providing a much needed pedestrian underpass to the road above. However, in order to accommodate the space needed for this, and the platforms below, the existing track required lowering by more than seven feet. To achieve this task, whilst still keeping the track open during the day, the bed underneath the track was excavated, and the track held up by a timber trestle work. Then, once excavation was complete and the new station constructed around the site, an army of over 900 workmen lowered the whole track simultaneously in one night, utilising overhead hooks to suspend the track when necessary. The hooks still remain.

District and Hammersmith and City line trains running into Aldgate East along two sides of the triangle (from Liverpool Street and from Tower Hill) pass through the site of the earlier station, most of which has been obliterated by the current junction alignment, although the extensive width and height and irregular shape of the tunnel can be observed.

Since the station was built completely under a widened road, and was built after concrete had started to be used as a construction material, the platforms have a particularly high headroom. Combined with the late 1930s style of tiling typical of the stations of the then London Passenger Transport Board, the platform area of the station presents a particularly airy and welcoming appearance, unusual on the underground at the time of construction. The tiling contains relief tiles, showing devices pertinent to London Transport and the area it served, were designed by Harold Stabler and made by the Poole Pottery.