I feel like in movies and video games, many shields are portrayed as being made of metal, and wooden shields being portrayed as inferior. However, many historical examples I have seen, such as the Roman scutum, are clearly wooden or wrapped in leather. To what degree was metal used in shields? What is an example of a high quality shield for a foot-soldier?
I don't believe fully metal shields came into being before the rotella, which were used mainly by the Spanish before they fully developed the tercio pike & shot formations. They only lasted for about 50-60 years before being made obselete.
I guess you could count bucklers as shields though but to what extent they were ALL made out metal is entirely dependent - I don't believe there was a trend of all metal or composite buckler construction dealienated by time period but all the bosses were made of iron.