It is the second-largest state by land area, with 47,614 km2 (18,384 sq mi), and fourth-largest in population (8 million in 2021) among the 16 Länder of the Federal Republic of Germany.

In the extreme west of Lower Saxony is the Emsland, an economically emerging but rather sparsely populated area, once dominated by inaccessible swamps.

The northern half of Lower Saxony, also known as the North German Plain, is almost invariably flat except for the gentle hills around the Bremen geestland.

Due to its gentle local climate and fertile soil, it is the state's largest area of fruit farming, its chief produce being apples.

The state's economy, population, and infrastructure are centred on the cities and towns of Hanover, Stadthagen, Celle, Braunschweig, Wolfsburg, Hildesheim, and Salzgitter.

Just under 20% of the land area of Lower Saxony is designated as nature parks, i.e.: Dümmer, Elbhöhen-Wendland, Elm-Lappwald, Harz, Lüneburger Heide, Münden, Terra.vita, Solling-Vogler, Lake Steinhude, Südheide, Weser Uplands, Wildeshausen Geest, Bourtanger Moor-Bargerveen.

The highest levels of precipitation are experienced in the Harz because the Lower Saxon part forms the windward side of this mountain range against which orographic rain falls.

During the Migration Period some of the Saxon peoples left their homeland in Holstein about the 3rd century and pushed southwards over the Elbe, where they expanded into the sparsely populated regions in the rest of the lowlands, in present-day Northwest Germany and the northeastern part of what is now the Netherlands.

At the same time a distinction was made with the eastern part of the old Saxon lands from the central German principalities later called Upper Saxony for dynastic reasons.

The majority of historic territories whose land now lies within Lower Saxony were sub-principalities of the medieval, Welf estates of the Duchy of Brunswick-Lüneburg.

Nevertheless, the entire Weser-Ems region (including the city of Bremen) were grouped in 1920 into a Lower Saxon Constituency Association (Wahlkreisverband IX (Niedersachsen)).

Nevertheless, some changes to the old state and provincial borders were made in 1937, notably including the city of Cuxhaven being fully integrated into the Prussian Province of Hanover under the Greater Hamburg Act.

At the end of the 1920s in the context of discussions about a reform of the Reich, and promoted by the expanding local heritage movement (Heimatbewegung), a 25-year conflict started between "Lower Saxony" and "Westphalia".

Its minister president, Hinrich Wilhelm Kopf, had already suggested in June 1945 the formation of a state of Lower Saxony, that was to include the largest possible region in the middle of the British Zone.

[12] Kopf's plan was ultimately based on a draft for the reform of the German Empire from the late 1920s by Georg Schnath and Kurt Brüning.

[14] Particularly in the districts where there was a political Catholicism the notion was widespread, that Oldenburg Münsterland and the Regierungsbezirk of Osnabrück should be part of a newly formed State of Westphalia.

But there were exceptions: The demands of Dutch politicians that the Netherlands should be given the German regions east of the Dutch-German border as war reparations, were roundly rejected at the London Conference of 26 March 1949.

→ see main article Dutch annexation of German territory after World War II The first Lower Saxon parliament or Landtag met on 9 December 1946.

Kopf's cabinet had to organise an improvement of food supplies and the reconstruction of the cities and towns destroyed by Allied air raids during the war years.

Hinrich Wilhelm Kopf remained – interrupted by the time in office of Heinrich Hellwege (1955–1959) – as the head of government in Lower Saxony until 1961.

Lower Saxony was at the western end of the direct escape route from East Prussia and had the longest border with the Soviet Zone.

Overall, Lower Saxony, with its large tracts of rural countryside and few urban centres, was one of the industrially weaker regions of the federal republic for a long time.

The arguments about the Gorleben Nuclear Waste Repository, that began during the time in office of minister president Ernst Albrecht (1976–1990), have played an important role in state and federal politics since the end of the 1970s.

Despite decades of gradual downsizing and restructuring, the carmaker Volkswagen with its five production plants within the state's borders still remains the single biggest private-sector employer, its world headquarters in Wolfsburg.

Due to the Volkswagen Law, which has recently been ruled illegal by the European Union's high court, the state of Lower Saxony is still the second-largest shareholder, owning 20.3% of the company.

Other mainstays of the Lower Saxon industrial sector include aviation (the region of Stade is called CFK-Valley), shipbuilding (such as Meyer Werft), biotechnology, and steel.

Medicine plays a major role; Hanover and Göttingen have two large University Medical Schools and hospitals, and Otto Bock in Duderstadt is the largest producer of prosthetics and associated componentry in the world.

Important branches today are the tourism industry with TUI AG in Hanover, one of Europe's largest travel companies, as well as trade and telecommunications.

Lower Saxony was one of the origins of the German environmentalist movement in reaction to the state government's support for underground nuclear waste disposal.

The composition of the parliament obeys the principle of proportional representation of the participating political parties, but it is also ensured that each constituency delegates one directly elected representative.