In 1203, King Valdemar II of Denmark conquered the area later comprising Saxe-Lauenburg, but it reverted to Albert I, Duke of Saxony in 1227.
In 1260, Albert I's sons Albert II and John I succeeded their father.
In 1269, 1272 and 1282, the brothers gradually divided their governing competences within the three territorially unconnected Saxon areas along the Elbe river (one called Land of Hadeln, another around Lauenburg upon Elbe and the third around Wittenberg upon Elbe), thus preparing a partition.

After John I's resignation, Albert II ruled with his minor nephews Albert III, Eric I and John II, who by 1296 definitely partitioned Saxony providing Saxe-Lauenburg for the brothers, and Saxe-Wittenberg for their uncle Albert II.
The last document, mentioning the brothers and their uncle Albert II as Saxon fellow dukes dates back to 1295.
A deed of 20 September 1296, mentions the Vierlande, Sadelbande (Land of Lauenburg), the Land of Ratzeburg, the Land of Darzing (later Amt Neuhaus), and the Land of Hadeln as the separate territory of the brothers.

 By 1303, the three jointly ruling brothers had partitioned Saxe-Lauenburg into three shares, however, Albert III died already in 1308, so that the surviving brothers established, after a territorial realignment in 1321, the Lauenburg Elder Line, with John II ruling Saxe-Bergedorf-Mölln, seated in Bergedorf and the Lauenburg Younger Line, with Eric I ruling Saxe-Ratzeburg-Lauenburg, seated in Lauenburg upon Elbe.
John II, the eldest brother, wielded the electoral privilege for the Lauenburg Ascanians, however, rivalled by their cousin Rudolph I of Saxe-Wittenberg.

In 1314, the dispute escalated into the election of two hostile German kings, the Habsburg Frederick III, the Fair, and his Wittelsbach cousin Louis IV, the Bavarian.
Louis received five of the seven votes, to wit Archbishop-Elector Baldwin of Trier, the legitimate King-Elector John of Bohemia, Duke John II of Saxe-Lauenburg using his claim as the Saxon prince-elector, Archbishop-Elector Peter of Mainz, and Prince-Elector Waldemar of Brandenburg.

Frederick the Fair received in the same election four of the seven votes, with the deposed King-Elector Henry of Bohemia, illegitimately assuming electoral power, Archbishop-Elector Henry II of Cologne, Louis's brother Prince-Elector Rudolph I of the Electorate of the Palatinate, and Duke Rudolph I of Saxe-Wittenberg, rivallingly claiming the Saxon prince-electoral power.
However, only Louis the Bavarian finally asserted himself as emperor of the Holy Roman Empire.
The Golden Bull of 1356, however, conclusively named the dukes of Saxe-Wittenberg as electors.

In 1370, John II's fourth successor Eric III of Saxe-Bergedorf-Mölln pawned the Herrschaft of Bergedorf, the Vierlande, half the Saxon Wood and Geesthacht to Lübeck in return for a credit of 16,262.5 Lübeck marks.
This acquisition included much of the trade route between Hamburg and Lübeck, thus providing a safe passage for freight between the cities.
Eric III only retained a life tenancy.

The city of Lübeck and Eric III had stipulated that, upon his death, Lübeck would be entitled to take possession of the pawned areas until his successors repaid the credit and simultaneously exercised the repurchase of Mölln (contracted in 1359), altogether amounting to the then enormous sum of 26,000 Lübeck Marks.

In 1401, Eric III died without issue.
The Lauenburg Elder Line was thus extinct in the male line and Eric III was succeeded by his second cousin Eric IV of Saxe-Ratzeburg-Lauenburg of the Younger Line.
In the same year, Eric IV, supported by his sons Eric (later ruling as Eric V) and John, forcefully captured the pawned areas without making any repayment, before Lübeck could take possession of them.
Lübeck acquiesced for the time being.

 In 1420, Eric V attacked Prince-Elector Frederick I of Brandenburg and Lübeck allied with Hamburg in support of Brandenburg.
Armies of both cities opened a second front and conquered Bergedorf, Riepenburg castle and the Esslingen river toll station (today's Zollenspieker Ferry).
This forced Er
In 1203, King Valdemar II of Denmark conquered the area later comprising Saxe-Lauenburg, but it reverted to Albert I, Duke of Saxony in 1227. In 1260, Albert I's sons Albert II and John I succeeded their father. In 1269, 1272 and 1282, the brothers gradually divided their governing competences within the three territorially unconnected Saxon areas along the Elbe river (one called Land of Hadeln, another around Lauenburg upon Elbe and the third around Wittenberg upon Elbe), thus preparing a partition.
After John I's resignation, Albert II ruled with his minor nephews Albert III, Eric I and John II, who by 1296 definitely partitioned Saxony providing Saxe-Lauenburg for the brothers, and Saxe-Wittenberg for their uncle Albert II. The last document, mentioning the brothers and their uncle Albert II as Saxon fellow dukes dates back to 1295. A deed of 20 September 1296, mentions the Vierlande, Sadelbande (Land of Lauenburg), the Land of Ratzeburg, the Land of Darzing (later Amt Neuhaus), and the Land of Hadeln as the separate territory of the brothers.
 By 1303, the three jointly ruling brothers had partitioned Saxe-Lauenburg into three shares, however, Albert III died already in 1308, so that the surviving brothers established, after a territorial realignment in 1321, the Lauenburg Elder Line, with John II ruling Saxe-Bergedorf-Mölln, seated in Bergedorf and the Lauenburg Younger Line, with Eric I ruling Saxe-Ratzeburg-Lauenburg, seated in Lauenburg upon Elbe. John II, the eldest brother, wielded the electoral privilege for the Lauenburg Ascanians, however, rivalled by their cousin Rudolph I of Saxe-Wittenberg.
In 1314, the dispute escalated into the election of two hostile German kings, the Habsburg Frederick III, the Fair, and his Wittelsbach cousin Louis IV, the Bavarian. Louis received five of the seven votes, to wit Archbishop-Elector Baldwin of Trier, the legitimate King-Elector John of Bohemia, Duke John II of Saxe-Lauenburg using his claim as the Saxon prince-elector, Archbishop-Elector Peter of Mainz, and Prince-Elector Waldemar of Brandenburg.
Frederick the Fair received in the same election four of the seven votes, with the deposed King-Elector Henry of Bohemia, illegitimately assuming electoral power, Archbishop-Elector Henry II of Cologne, Louis's brother Prince-Elector Rudolph I of the Electorate of the Palatinate, and Duke Rudolph I of Saxe-Wittenberg, rivallingly claiming the Saxon prince-electoral power. However, only Louis the Bavarian finally asserted himself as emperor of the Holy Roman Empire. The Golden Bull of 1356, however, conclusively named the dukes of Saxe-Wittenberg as electors.
In 1370, John II's fourth successor Eric III of Saxe-Bergedorf-Mölln pawned the Herrschaft of Bergedorf, the Vierlande, half the Saxon Wood and Geesthacht to Lübeck in return for a credit of 16,262.5 Lübeck marks. This acquisition included much of the trade route between Hamburg and Lübeck, thus providing a safe passage for freight between the cities. Eric III only retained a life tenancy.
The city of Lübeck and Eric III had stipulated that, upon his death, Lübeck would be entitled to take possession of the pawned areas until his successors repaid the credit and simultaneously exercised the repurchase of Mölln (contracted in 1359), altogether amounting to the then enormous sum of 26,000 Lübeck Marks.
In 1401, Eric III died without issue. The Lauenburg Elder Line was thus extinct in the male line and Eric III was succeeded by his second cousin Eric IV of Saxe-Ratzeburg-Lauenburg of the Younger Line. In the same year, Eric IV, supported by his sons Eric (later ruling as Eric V) and John, forcefully captured the pawned areas without making any repayment, before Lübeck could take possession of them. Lübeck acquiesced for the time being.
 In 1420, Eric V attacked Prince-Elector Frederick I of Brandenburg and Lübeck allied with Hamburg in support of Brandenburg. Armies of both cities opened a second front and conquered Bergedorf, Riepenburg castle and the Esslingen river toll station (today's Zollenspieker Ferry). This forced Er
Saxe-Lauenburg