The Foundation was born in 1997 on the occasion of the twentieth anniversary of the death of Carlo Leone Montandon following the wishes of his daughter, Mariena Mondelli Montandon.
In honour of the latter, who passed away 6 October 2003, the foundation adopted the name of “Fondation Carlo Leone et Mariena Montandon”.

The Foundation is based in Sierre, in the Swiss canton of Vallese and is subject to Swiss law.

While aiming to address not only Switzerland, but all countries without distinction, the Foundation maintains a privileged relationship with Italy, where both Carlo Leone Montandon and his daughter Mariena lived and worked.