In 333 BCE, Antipater defeats the Spartans at the Battle of Megalopolis and forces them into what we now call the League of Corinth. So let's keep now going back to where Alexander is. Antipater clearly was competent at maintaining power in Greece, and the next major battle that Alexander and his troops face is at Isis. And what makes Isis significant is that they are hugely outnumbered, historians disagree by how much they're outnumbered. Remember, we said Alexander's forces were around 40 or 50,000, while the Persians at Isis, depending on which account you look at, were at least 150,000, probably over 100,000. More ancient accounts talk about many hundreds of thousands, or even a million troops. What also made Isis significant is this is where, this is the first time that Darius III, the Shah-in-Shah, the king of Persia, directly confronts Alexander.