The territory of the County of Diepholz at its greatest extent in the sixteenth century stretched from Colnrade and Goldenstedt in the north to Wehdem, Dielingen and Lemförde in the south.

Their properties in Barnstorf, Goldenstedt and Colnrade fell under the full jurisdiction of the Noble Lords from 1291 in their capacity as holders of the Vicecomitat of Sudholte but was a fief of the Bishop of Munster.

[5] Whilst their origins go further back in time, the family name first appears in 1160 (in Latinised German) as de Thefholte,[6] and a continuous genealogy of the dynasty only starts with Gottschalk I (cited 1177–1205).

[10] The German historian Carl Heinrich Niedberding speculated, based on the geographical location of these earliest known estates, that the Noble Lords of Diepholz might descend from the Saxon leader Widukind, but noted that there was no firm proof for such a descent.

In order to prevent a division of the territory's modest resources, younger sons tended to enter religious life as canons in neighbouring bishoprics such as Osnabrück, Minden, Bremen and Cologne, where some of them also ruled as bishops.

[14] Under the joint rule of the brothers Rudolf II and Konrad V (cited 1267–1302), the borders of the Lordship were forcefully expanded and sovereignty attained within their core territories by the acquisition in 1291 of the Vicecomitat of Sudholte, which gave them full jurisdiction over their subjects in the parishes of Drebber, Barnstorf and Goldenstedt.

The marriage dowry included properties in the surroundings of Wagenfeld, Bokel and Struten, which consolidated the dynasty's hold on the lands around Auburg castle to the east of their territories.

[24] Under constant threat from his more powerful neighbours and after endless hostilities with the Bishop of Minden, Rudolf VIII, son of Otto IV and Heilwig van Bronkhorst, abdicated his absolute sovereignty over Diepholz in 1510 and recognised the Duke of Brunswick-Lüneburg as his liege lord in return for the promise of his protection.

[25] The moor-covered territory of Diepholz had never been particularly wealthy and from Rudolf VIII's reign onwards the dynasty continuously struggled to cover the costs of its administration and the obligations of their semi-sovereign lifestyle.

[30] When Friedrich I died in 1529, whilst visiting his sister Imgard in the Abbey of Essen, his brother, Johann VI, returned from Cologne and seized power in Diepholz.

He formally agreed with his sister-in-law, Eva of Regenstein, that he would conclude a morganatic marriage in order not to impinge on the rights of his nephew, Rudolf IX, son of Friedrich I, when he came of age.

Irmgard of Diepholz, daughter of Rudolf VIII and Elisabeth of Lippe, had entered Essen Abbey as a religious in 1505 and slowly rose through the ranks to become Princess-Abbess in 1561.

[34] Rudolf IV, succeeded his father as sovereign of Diepholz in 1484, thanks to the premature death of his older brother, Konrad XI (died 1483), who had left progeny by an unknown partner.

[36] Otto was initially a commander of the forces of Count Edzard I of East-Frisia in the Saxon Feud, but later became a supporter and legate of the Habsburg dynasty in the Netherlands, who appointed him as imperial warden in Amersfoort in 1538.