Alain I de Rohan

Alain I de Rohan (1084–1147), also known as le Noir, was the 1st Viscount de Rohan and Viscount of Castelnoec. He was the third son of Eudon I de Porhoët, viscount of Porhoët, and Emma de Léon (daughter of Guyomarch II, Viscount de Léon).

He received as his inheritance, the sparsely populated western Porhoët, in 1116. He also owned a castle at Castennec and constructed another on the shores of the Oust which he named Rohan, the name he passed on to his descendants. In 1128, Alain de Rohan finished constructing his permanent residences and founded the Priory de la Coarde at Castennec for the monks at Redon Abbey, and a priory for Marmoutier Abbey near the château de Rohan.

He had three children:

• Alain II de Rohan, 2nd Viscount de Rohan,
• Josselin
• Eudes, Viscount of Porhoet, who in 1148 became second husband to Bertha, Duchess of Brittany, daughter of Conan III of Brittany, and Maud FitzRoy, Duchess of Brittany. They had no descendants.