After Pontius Pilate sent Jesus to be crucified,
the crowd of people made fun of him, put a robe on him and gave him a crown made of sharp thorns to wear to pretend like he was a king since he said he was the king of the Jews.
Even though Jesus was very powerful, he did not fight back because he knew it was all part of God's plan for him to die on the cross.
(from: wikipedia - crown of thorns)
Kid Facts - Blast from the past: Jesus' Miracles - Healing on the Sabbath
