Leonardo da Vinci, The Virgin of the Rocks, c. 1491-1508

[alasion1]

since when did john the baptist carry the cross?

[MandyJMaddison]

@alasion1 In Renaissance pictures, John the Baptist usually carries a thin cross made of reeds, with a banner twisted around it as his symbol. You can just see the banner near his hands. It says "Agnus Dei": "The Lamb of God". Neither the cross or the words refer to John himself. They both refer to John prophesy that Jesus was "the Christ" and "the lamb of God who takes away the sins of the world" i.e. a blood sacrifice. In Verrocchio and Leonardo's "Baptism of Christ" it is more clear.

[alasion1]

@MandyJMaddison i stand corrected.you are obviously an expert in this field.ty