In the children's rhyme, "Jack and Jill", Jack fell down and broke his crown. This is a reference to the biblical story of King Solomon, who was said to have broken his crown when he fell from his throne.
In the children's rhyme, when Jack fell down, he broke his crown. It's just a reference to scriptures concerning King Solomon was rumor to have broken his crown when he fell down.
In the children's rhyme "Jack and Jill," when Jack fell down, he broke his crown. The line goes, "Jack and Jill went up the hill, to fetch a pail of water. Jack fell down and broke his crown, and Jill came tumbling after."