While Alexander and his troops spent a month in Babylon amidst its fabled luxuries and pleasures, all was not well back home in Macedon.

The homeland in 330 BCE, threatened by mass invasion on two fronts, was in real danger of falling. Had this occurred, not even Alexander could have kept his men in Asia. Darius most probably would not have been killed and The Persian Empire would most certainly have survived. Everything hinged upon what Alexander later termed, "The War Of Mice".

In the Peloponnese, Agis, king of Sparta, in the belief that while the cat's away the mice may play,took the opportunity to march north in an attempt to seize Macedon.He was quickly joined in alliance with other Greek states including Elis, Tagea, and Arcadia. A force of 30,000 soldiers was aimed north at the heart of Macedonian power.

At the same time Memnon, Macedonian governor of Thrace, revolted and massed his armies on the eastern borders of Macedon. With Agis approaching from the south and Memnon from the east, Antipater was confronted with a pincer attack on two fronts. To make matters worse, there was the real threat of Athens allying with Sparta. Unknown to Alexander, he faced a peril in Europe as great as that which he faced in Asia. If Macedon fell his supply lines would be cut, his men demoralized, and his conquest brought to a halt.

Antipater reacted quickly. He marched his entire army east to confront Memnon in full force thus exposing his southern border. It was a brave move worthy of Alexander, himself. Memnon was counting upon the Macedonians being split into two smaller armies on two fronts. When he saw the size of Antipater's force he capitulated at once and negotiated a deal with Antipater which left him still in control of Thrace as Alexander's governor.The need for haste with Agis moving north from Sparta made Antipater generous indeed and Memnon with some diplomacy, remained in power for some three years more until he was called out to India to deliver more troops to Alexander. After this, he is never heard of again.

Alexander first learned of the troubles in Europe from Amyntas who had just returned from there with reinforcements. They met as Alexander was marching south from Babylon to Susa, but it would be months before he learned of the outcome. He at once dispatched, Menes his inspector general, to Greece with 3000 talents to pay all the expenses of the impending conflict and to offer bribes to influential Athenians to vote against an alliance with Sparta. Bribes of 50 to 100 talents, an enormous fortune at the time, were offered to various prominent men in Athens. Who might have accepted these bribes we do no know, but it is recorded that two citizens, Phocion and Xenocretes refused them.

Agis was not as lucky as Memnon; with his eastern border secure, Antipater turned the full force of the Macedonian army south to face Agis. It was a rout. Agis was killed in the battle of Megalopolis and the armies disbanded. A victorious Macedon was secure.

Due to the state of communications of the time, Alexander did not hear of all of this until some months after it was all over. It was only when he was in Persepolis that he learned of the victories of Antipater. He must have been living in apprehension for some time as he was aware of the importance of the outcome to his campaign.It was in Persepolis that he informed the soldiers of the war which had been fought and won in Greece and it was here that he coined the term, "A War Of Mice."If indeed, he did use those words, he most certainly realized the ernest importance of Antipater's contribution to his own successes in that War Of Mice.