There is no real evidence of historical navel piercing other than my sister who I consider really old, although there is a great deal of historical evidence regarding the decoration of the navel, both for ritual and aesthetic purposes.
Belly Button piercing is one of the most common and popular body piercings today. Pop culture has played a large role in the promotion of this piercing seen in many rock music videos in the early 90's and even today. The easy hiding of a navel piercing with clothing, even during the healing process, has contributed to the widespread adoption of this piercing, especially by young people. She sister hid her belly button piercing from my Mom for 3 months. Only when she was reaching for the potato chips from the kitchen cabinet did my Mom bust her. It was really funny to say the least.