When did nailed iron horseshoes first appear in Europe?

While some sources suggest that horseshoes were a Roman invention, the nailed iron horseshoe as it is recognized today first appeared in Europe around the 5th century CE, introduced by invaders from the East.12

Although Roman poets mentioned the loss of a mule's shoe as early as the 1st century BCE, these were likely different from the modern nailed variety. Archaeological evidence for the nailed iron horseshoe is confirmed by a specimen found in the tomb of the Frankish king Childeric I at Tournai, Belgium, which dates to the 5th century CE. Prior to this, various types of hoof protection were used by migratory Eurasian tribes as early as the 2nd century BCE.12