The western part of the Duchy, the Agenais, was lost in a few weeks.

This left only a small part of the Duchy for Henry, and he was often short of funds.

In 1266 the area became part of the Duchy of Lancaster.

In 1350 it became part of the Duchy of Milan.

In 1809, it became part of the Duchy of Warsaw.

It was created from a part of the Duchy of Brittany.

During the 9th century, the area was part of the Duchy of Saxony.

It still forms a part of the Duchy of Lancaster.

It used to be part of the Duchy of Bavaria until the 12th century.

It became part of the Duchy of Savoy in 1407.