Armin, Prince of Lippe
Armin, Prince of Lippe ("Armin Leopold Ernst Bruno Heinrich
Willa August Fürst zur Lippe"; 18 August 1924 – 20 August 2015, also in Detmold) was the son of Leopold IV, Prince of Lippe and his second wife, Princess Anna of Ysenburg and Büdingen.
Otto, Lord of Lippe
Otto, Lord of Lippe was the ruling Count of Lippe- Lemgo from 1344 until his death.
Princess Anna of Ysenburg and Büdingen
Princess Anna of Ysenburg and Büdingen (10 February 1886, Büdingen – 8 February 1980, Detmold) was the youngest child of Bruno, 3rd Prince of Ysenburg and Büdingen and his wife, Countess Bertha of Castell-Rüdenhausen.
Through her second marriage to Leopold IV, Prince of Lippe, Anna was the titular Princess consort of Lippe.
Leopold I, Prince of Lippe
Leopold I of Lippe( 2 December 1767 – 5 November 1802) was a Prince of Lippe.
Ernest, Count of Lippe-Biesterfeld
Ernst, Count of Lippe- Biesterfeld(" Ernst Kasimir Friedrich Karl Eberhard"; 9 June 1842 – 26 September 1904) was the head of the Lippe- Biesterfeld line of the House of Lippe.
From 1897 until his death he was the regent of the Principality of Lippe.
Herman Adolph, Count of Lippe
Herman Adolph, Count of Lippe- Detmold( 1616 – 1666) was a ruler of the county of Lippe.
Stephan, Prince of Lippe
Stephan, Prince of Lippe(" Stephan Leopold Justus Richard") was born on 24 May 1959 in Detmold, Germany.
He is the son of Armin Leopold Ernst Bruno Heinrich Willa August Prince of Lippe and Traute Becker, and the head of the House of Lippe since 2015.
Frederick Charles Augustus, Count of Lippe
Count Frederick Charles Augustus of Lippe- Biesterfeld( 20 January 1706 in Biesterfeld – 31 July 1781 in Friedrichsruh) was a Count of Lippe and Lord of Lippe- Biesterfeld, Sternberg and Schwalenberg and a Knight of the Order of the Red Eagle.
He was the eldest son of Rudolf Ferdinand of Lippe- Sternberg- Schwalenberg( 17 March 1671 – 12 July 1736) and Louise Juliane of Kunowitz( 21 August 1671 – 21 October 1754) and the grandson of Jobst Herman of Lippe- Biesterfeld.
Simon V, Count of Lippe
Count Simon V of Lippe (1471September 17, 1536) was Noble Lord of Lippe, and from 1528 Count of Lippe.
During his reign, the Reformation was introduced in Lippe.
Prince Friedrich Wilhelm of Lippe
Friedrich Wilhelm of Lippe( born 7 September 1947) is a claimant to the headship of the House of Lippe.

Question: Who is Armin, Prince Of Lippe's maternal grandfather?
Answer: Bruno, 3rd Prince of Ysenburg and Büdingen