18th Century Pockets
This style of pocket is great so long as skirts are full and there are hoops or hip pads holding the skirts away from the body, but when the ideal silhouette changes to the body-conscious one that we’re all familiar with from the Regency (in the late 1790s) a lumpy pocket under your skirts is not such a great idea any more. Plus, if you’re wearing a round gown, there’ no way to reach the pocket.
Thus is born the ridicule. From what I’ve seen it looks like women simple started carrying one pocket on a string like a purse. The pocket quickly transformed into the much smaller ridicules seen during the Regency, and by the middle of the Victorian era even the name had changed, becoming the reticule.