In France, the Catholic League, led by the Duke of Guise, declares
Henry of Navarre to be incapable of inheriting the French throne.
In an attempt to gain control for himself over the League, Henry
III signs the Treaty of Nemours with the House of Guise. It
cancelled all previous concessions to the Huguenots and ruled that
Catholicism was the only lawful religion of France. As a
consequence, anyone who practised another religious faith could not
hold public office, including the throne.
Citation:
Editors. "Catholic League declares Navarre incapable of inheriting the throne".
The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15313, accessed 20 June 2013.]