Pyong Ahn hyung
These forms were created in Okinawa by Anko Itosu in the late 1800's and introduced into school systems in the early 1900's. They are simplified versions of forms already being taught at the time, such as Bassai and Kong Sang Koon (Kusanku). These forms are shared by tons of Karate styles, from Shotokan, Wado Ryu, Isshin Ryu, Shito ryu, Kyokushin, and many more. This is pretty common knowledge.
But what you may not know, is the order is different depending on the style. For instance, in Wado Ryu what we call Pyong Ahn Cho Dan in Tang Soo Do, is actually Pinan Nidan (Pyong Ahn E Dan). In fact, most of the Okinawan styles have our E-Dan, as Cho Dan. So where did the change come from? Tokyo, Japan... Funakoshi Gichin switched the order of the first two Pinan forms and used the Japanese pronunciation "Heian". He did this because the original second form was easier to learn than the first.
In Tang Soo Do, Hwang Kee agreed with Funakoshi and used this order as well.
All calligraphy done by Master Dan Bernardo