CROESUS and SOLON – Who is the happiest man?

Croesus, king of ancient Lydia, well- known for his wealth, invites Solon, one of the seven wise men asking him “who is the happiest man in the world.”

What was Solon’s answer ? How does Croesus respond to it ? When and why did  the rich king really understood what wealth, happiness, free will and destiny really mean?