The first part of the Emperor's Harbors dates back to as early as 1872, when the Senate of Bremen decided to construct a third harbour basin in Bremerhaven (after Alter and Neuer Hafen). That basin was planned by the Bremerhaven head of port construction of the time, Carl Friedrich Hanckes (1829-1891). Finished in 1875, it was equipped with a lock into the Weser in 1876. This was decommissioned in 1937.
But this extension was not sufficient for the needs of the mighty North German Lloyd (founded in 1857), the most influential Bremen shipping company of the time. In 1881, the existing new basin saw limited extension, but it required a further extension during the time before the outbreak of World War I to make the port capacity adequate for the time. In 1892, works were commenced and headed by the Bremerhaven port engineers Rudolf Rudloff (1851-1922) and Federico Claussen (1865-1940). Emperor's Harbor II was excavated from 1906 to 1908 and was extended from 1925 to 1927. Further works in brief: Emperor's Harbor III (1907 to 1909) and the connecting Verbindungshafen (1908 to 1915). Part of these comprehensive measures was the construction of the Emperor's lock, inaugurated in 1897 with a chamber length of 222.2 metres. This was the largest lock of that time and was able to handle Lloyd´s biggest liners.
North German Lloyd had moved with its transatlantic service across the Weser to Nordenham in 1890 because of insufficient facilities at Bremerhaven. Thanks to the changes there, the company was able to return in 1897.