[1] A fifth brother, Otto (or Ato), was Bishop of Pallars, which allowed the counts, especially Isarn, to effectively control the Church in their territories.
[2] In 904 he was captured along with seven hundred others during a raid by the Qasawi Muslim lord of Lleida, Llop ibn Muhammad.
[3] From the Códice de Roda we know that he remained a prisoner at Tudela until 918, when he was liberated by his cousin, King Sancho I of Pamplona.
[b] As count, Isarn founded a convent, Sant Pere de Burgal, at Burghals and made his daughter Ermengardis its first abbess in 945.
[4] At that date he signed a charter as Domnus Isarnus comes et marchio dum resideret in Paliarensis regno: "Lord Isarn, count and margrave, while residing in the kingdom of Pallars.