What is the origin of the idiom "a beggar on horseback" and when to use it?

The idiom "a beggar on horseback" has its origins in the early 17th century. The phrase is often attributed to John Heywood, an English playwright and poet, who used it in his works. It is used to describe someone who, after experiencing a significant change in fortune or status, becomes arrogant, wasteful, or irresponsible due to their newfound power or wealth.