Countess Armgard of Rietberg (also: Irmgard; died 13 July 1584) was from 1562 to 1584 Countess of Rietberg in her own right.
•
On 27 September 1576, Armgard and Walburgis divided their inheritance: Armgard received Rietberg; Walburgis received the Harlingerland.
•
Because she had no brothers, Armgard and her sister Walburgis inherited his possessions.
After the death of her husband in 1934, Armgard managed an estate in Reckenwalde, Province of Brandenburg (now Wojnowo, Poland), together with her partner Alexis Pantchoulidzew.
•
The SS demanded in September 1944 in Recke, one of Armgard's properties, Schloss Woynowo Walde for military purposes.
Armgard (18 December 1883 – 27 April 1971), married in 1905 to Count Bodo of Oeynhausen, divorced in 1908, no issue; Married secondly in 1909 to Prince Bernhard of Lippe-Biesterfeld, had issue.