Ralph I, Lord of Coucy
Ralph of Coucy,( c. 1134 – 1191), lord of Coucy, lord of Marle, La Fère, Crécy( sur- Serre), Vervins, Pinon, Landouzy( la- Ville), and Fontaine( lès- Vervins).
He was the son of Enguerrand II, Lord of Coucy and Agnes de Beaugency.
Nicholas IV of Werle
Nicholas IV, Lord of Werle[ Goldberg], nicknamed" PoogenogePig's eyes")( born: before 1331; died: between 14 March and 13 November 1354) was from 1350 to 1354 to Lord of Werle- Goldberg.
Simon IV, Lord of Lippe
Simon IV, Lord of Lippe( – 11 August 1429) was the ruling Lord of Lippe from 1415 until his death.
Enguerrand V de Coucy
Enguerrand V, Lord of Coucy( after 1321) inherited the title of Lord of Coucy and castle from his maternal uncle, Enguerrand IV in 1311.
He was also lord of Oisy and Montmirail.
Raoul II, Lord of Coucy
Raoul II, Lord of Coucy( died 1250) was a son of Enguerrand III and his wife Maria of Oisy.
In 1246 he succeeded his father as lord of Coucy.
Raoul died at the siege of El Mansoura in Egypt during the Seventh Crusade.
Raoul married Elisabeth, daughter of Walter III of Châtillon, and later remarried to Philippe of Dammartin, daughter of Simon of Dammartin.
Bernard IV, Lord of Lippe
Bernhard IV, Lord of Lippe( in Brake – June 1275) was a ruling Lord of Lippe.
Enguerrand IV de Coucy
Enguerrand IV, Lord of Coucy (c. 1236 – 1311) was the son of Enguerrand III, Lord of Coucy and Marie de Montmirail.
He succeeded his older brother Raoul II, Lord of Coucy, serving as the Sire de Coucy from his brother's death in 1250 until his own in 1311.
Enguerrand III, Lord of Coucy
Enguerrand III de Boves, Lord of Coucy (c.1182–1242) was the eldest son and successor of Ralph I, Lord of Coucy (c. 1134 – 1191) and Alix de Dreux.
He succeeded as Lord of Coucy ("sieur de Couci") in 1191, and held it until his death; he was also lord of Marle and Boves.
Thomas, Lord of Coucy
Thomas of Marle, Lord of Coucy and Boves, was born in 1073 to Enguerrand I of Boves, the Lord of Coucy and his wife Adele of Marle.
After the death of his father, Enguerrand I, Thomas would become the Lord of Coucy and his family's other holdings.
As the best- known of the Lords of Coucy, Thomas of Marle would become infamous for his aggressive and brutal tactics in war and his continued rebellion against the authority of Louis VI.
John IV, Lord of Arkel
John IV, Lord of Arkel( also known as" Jan Herbaren van Arkel"; d. 5 May 1360) was Lord of Arkel from 1326 until his death.

Question: Who is Enguerrand Iv De Coucy's paternal grandfather?
Answer: Ralph I, Lord of Coucy