Cross symbol used by the Huguenots, French Protestants in 16th and 17th century. Today It also an official symbol of the Eglise des protestants reformé de France.
Own work based on: Kreuz-hugenotten.jpg:   and Huguenot cross.svg:
File:Kreuz-hugenotten.jpg: Nicetry (based on the work of Ulrich Fuchs)
File:Huguenot cross.svg: Syryatsu
derivative work Svgalbertian