Pepin was born c. 815 and was the first count of Vermandois, lord of Senlis, Peronne, and Saint Quentin.
Pepin first appears in 834 as a count to the north of the Seine and then appears as same again in 840. In that year, he supported Lothair I against Louis the Pious.
Pepin's wife is unknown, but his heir inherited much Nibelungid territory and so historian K. F. Werner hypothesised a marriage to a daughter of Theodoric Nibelung. Their children were:
Bernard who lived from 844 until after 893. He was count of Laon
Pepin who lived from c. 846 until 893. He was count of Senlis and lord of Valois from 877 until 893)
Cunigunda
Gunhilde De Vermandois who married first the Margrave Berengar I of Neustria and then Count Guy of Senlis
