Regency Era Slippers

From the seller:

A dainty pair of 1820’s ivory satin straight shoes.  The shoes are lined with linen and have the number 4m stamped inside.  One of the shoes retains its original silk ribbon ankle ties.  The shoes are in very good condition.  There is a one inch split in the fabric along the edge of the leather sole.  Length 10 inches Width 2 ½ inches.

From Me: 

Straight last shoes were common well into the 19th Century.  The idea of a left and right shoe didn't really take off until the 1840's.