After its dynastic partition in 1267 Harburg was part of the Brunswick-Lunenburgian Principality of Lunenburg (Celle).

With the latter's death the Brunswick-Lunenburgian branch of Harburg was extinct in the male line and the area reunited with Lunenburg-Celle proper.

In 1705 the Lunenburg-Celle line was extinct and the principality inherited by Duke George Louis of Brunswick and Lunenburg (Calenberg), ruling the Principality of Calenberg, which managed to be upgraded as Electorate of Brunswick and Lunenburg, colloquially named after its capital Electorate of Hanover, in 1708.

During this period (in 1720–23) the town was the notional headquarters of the abortive Harburg Company which, with a charter from King George I of Great Britain and funded by a dubious lottery scheme, was supposed to deepen the river and improve the harbour.

When the lottery was forbidden to operate in England as fraudulent and illegal, the scheme foundered.

Harburg then became the capital of the Canton d'Harbourg within the Arrondissement de Lunebourg of the Département des Bouches-de-l'Elbe.

On 1 April 1937 Harburg-Wilhelmsburg was disentangled from Prussia – according to the "Greater Hamburg Act" – and ceded to the state of Hamburg, which on 1 April 1938 incorporated the city into a unitary city state municipality (Einheitsgemeinde), thus abolishing Harburg(-Wilhelmsburg)'s municipal independence dating back to 1288.

Harburg, situated in the southern side of Hamburg, borders with the quarters of Neuland, Gut Moor, Rönneburg, Wilstorf, Eißendorf, Heimfeld and Wilhelmsburg (in the district of Mitte).

According to the Department of Motor Vehicles (Kraftfahrt-Bundesamt), 5,148 private cars were registered (246 cars/1000 people) in the quarter.