Walkers

A new study suggests that early hominids (that's human beings in non-science speak) had difficulty running due to the lack of Achilles tendons.
The scientist conducting the research said, "What we need to discover now is when in our evolution did we develop an Achilles tendon, as knowing this will help unravel the mystery of our origins."

So we can date our origins to around the time of the Trojan War.