The peplum trend first became commercially popular during the 30s and 40s. It was a way to add flair and shape to classic skirt and blouse combos. Christian Dior's designs with the peplum were part of the reason it became incredibly popular during this time period. The silhouette created a more defined hourglass shape, which was popular during that time period.
The modern peplum style is a little higher than in previous decades and comes in many different forms. The key to making the peplum look modern and flattering is to always try it on. Different forms of peplum fit people differently and you want to make sure that you are buying something that will look flattering on you. You want the flair to go out right underneath your waist.
Here is some more peplum style inspiration to help you pull off the flattering trend. Remember to always try on any piece of clothing with peplum! You'll thank me later.