Plywood was used for shields by the Romans, I'm fairly certain the Vikings, and wikipedia mentions the Greeks and Egyptians used it as well. From what I can tell from a quick google, it does seem to be a casualty of the Dark ages though.
https://www.bostonglobe.com/2021/01/25/nation/weekend-riotin...
The Persians (and their allies) used wicker shields that chose light weight over protection [1].
More recently, there was also a video floating around recently of how protesters were building Viking shield walls to protect themselves [2]
0 - https://amzn.to/39n23Jx 1 - https://en.wikipedia.org/wiki/Sparabara 2 - https://twitter.com/joshuapotash/status/1291962889323020288?...