Its ruling margraves were established as prestigious prince-electors in the Golden Bull of 1356, allowing them to vote in the election of the Holy Roman Emperor.

Geographically it encompassed the majority of the present-day German states of Brandenburg and Berlin, the Altmark (the northern third of Saxony-Anhalt), and the Neumark (now divided between Poland's Lubusz and West Pomeranian Voivodeships).

The depressions are taken up by rivers and chains of lakes with marsh and boggy soil along the shores; once used for peat collection, the riverbanks are now mostly drained and dry.

The approximately 230 km-long range of hills in the Mark's south begins in the Lusatian Highlands (near Żary (Sorau)) and continues past Trzebiel (Triebel) and Spremberg, then to the northwest through Calau, and ends in the bare and dry Fläming.

The region is predominantly marked by dry, sandy soil, wide stretches of which have pine trees and erica plants, or heath.

[citation needed] Mark Brandenburg has a cool, continental climate, with temperatures averaging near 0 °C (32 °F) in January and February and near 18 °C (64 °F) in July and August.

By the eighth century, Slavic Wends, such as the Sprewane and Hevelli (Havolane or Stodorans), started to move into the Brandenburg area.

King Henry the Fowler started governing in the region in 928–929, allowing Emperor Otto I to establish the Northern March under Margrave Gero in 936 during the German Ostsiedlung.

From 1123 to 1125 Albert developed contacts with Pribislav, who served as the godfather for the Ascanian's first son, Otto, and gave the boy the Zauche region as a christening present in 1134.

In the same year, Emperor Lothair III named Albert margrave of the Northern March and raised Pribislav to the status of king, although that was later rescinded.

In contrast to their leaders who had accepted Christianity, the Havolane population still worshipped old Slavic deities and opposed Albert's assumption of power.

The territorial limits of the original margraviate differed from the area of the current Bundesland Brandenburg, consisting merely of the Havelland and Zauche regions.

In the following 150 years the Ascanians succeeded in winning the Uckermark, Teltow, and Barnim regions east of the Havel and Nuthe, thereby extending the Mark to the Oder River.

The Neumark ("New March") east of the Oder was acquired gradually through purchases, marriages, and aid to the Piast dynasty of Poland.

[6] Because of the sandy soil prevalent in Brandenburg, the agriculturally meager principality was denigrated as "the sandbox of the Holy Roman Empire".

After the capture of territory along the Elbe and Havel Rivers in the 1160s, Flemish and Dutch settlers from flooded regions in Holland used their expertise to build dikes in Brandenburg.

The middle of the 13th century was a time of important developments for the Ascanian House, as it won Stettin (Szczecin) and the Uckermark (1250), although the former was later lost to the Duchy of Pomerania.

The death of Magrave Waldemar in 1319 sparked a conflict between the neighbouring principalities of Brunswick-Lüneburg, Mecklenburg, Saxe-Wittenberg, Pomerania-Wolgast, Jawor and Żagań, for control of different parts of the Margraviate.

[8] By February 1322, eastern outskirts of the Lubusz Land with Torzym and Sulęcin and the Międzyrzecz castellany were controlled by Duke Henry IV the Faithful of Żagań.

A year later he lost the town Deutsch Krone (Wałcz), annexed from Greater Poland by Brandenburg in 1296, to Polish King Casimir the Great.

The Landbuch ("land book", i.e. estate register) of Charles IV, a source for the history of medieval settlement in Brandenburg, originated during this time.

Under the Wittelsbach and Luxembourg margraves, Brandenburg fell increasingly under the control of the local nobility as central authority declined.

[14] In return for supporting Sigismund as Holy Roman Emperor at Frankfurt in 1410, Frederick VI of Nuremberg, a burgrave of the House of Hohenzollern, was granted hereditary control over Brandenburg in 1411.

Frederick's formal investiture with the Kurmark, or electoral march, and his appointment as Archchamberlain of the Holy Roman Empire occurred on 18 April 1417, also during the Council of Constance.

The Hohenzollerns of Brandenburg sought to expand their power base from their relatively meager possessions, although this brought them into conflict with neighboring states.

At the end of the war in 1648, Brandenburg was recognized as the possessor of approximately half the inheritance, comprising the Duchy of Cleves in the Rhineland and the Counties of Mark and Ravensberg in Westphalia.

In this way, the fortuitous marriage of John Sigismund to Anna of Prussia, and the deaths of her maternal uncle in 1609 and her father in 1618 without immediate male heirs, proved to be the key events by which Brandenburg acquired territory both in the Rhineland and on the Baltic coast.

Prussia, unlike Brandenburg, lay outside the Holy Roman Empire, within which only the emperor and the ruler of Bohemia could call themselves king.

As king was a more prestigious title than prince-elector, the territories of the Hohenzollerns became known as the Kingdom of Prussia, although their power base remained in Brandenburg.

Legally, Brandenburg was still part of the Holy Roman Empire, ruled by the Hohenzollerns in personal union with the Prussian kingdom over which they were fully sovereign.