[3] He made his solemn vows as a full Knight of Justice on 11 May 2011 at the church Sainte-Élisabeth-de-Hongrie in Paris.
[4] A Knight Grand Cross of Justice, he was elected to a five-year term as a member of the Sovereign Council in May 2014.
[5] He was elected to a second five-year term as a member of the Sovereign Council in May 2019.
[6] That term ended when Pope Francis reorganized the leadership of the Sovereign Order of Malta on 3 September 2022 and appointed him Grand Commander of the Order of Malta.
Rousseau is President of the Historical Commission for the beatification of Empress Zita of Austria.