A canton is an administrative local area, commonly a grouping of village, or a part a huge town. You could translate 'canton de Soissons' by something along the lines of 'Soissons council area'
Louis de Soissons was born in 1890.
de (french) = of (english)
De quelle? in French means "Of what?" in English.
Coup de grâce in French is "killing blow" in English.
Terrain de sport in French is "sports ground" in English.
Pas de soucis! in French means "No worries!" in English.
Coup de la... in French means "blow of the..." in English.
Compagnie de gestion in French means "management company" in English.
Qui est de Paris? in French is "Who is from Paris?" in English.
Café de l'amour in French means "coffeehouse of love" in English.
Café de Toi in French means "Coffeehouse of You" or "Your Coffeehouse" in English.
Chaîne de montagnes in French means "mountain range" in English.