Complex sentence: Its white fleurs-de-lis (symbols of purity) and blue field (symbolizing Heaven) come from a banner honouring the Virgin Mary, reputedly carried by French-Canadian militia at General Louis-Joseph de Montcalm's victory at Carillon.
Split into simpler sentences: Its white fleurs-de-lis (symbols of purity) and blue field (symbolizing Heaven) come from a banner honouring the Virgin Mary. One such was reputedly carried by French-Canadian militia at General Louis-Joseph de Montcalm's victory at Carillon.