The Athenian ‘Long Walls’ were fortifications erected after Xerxes’ invasion of Greece. Building of the walls began as part of a rebuilding programme after Athens was sacked and burned by the Persians. Once the Athenians returned to their city, having defeated the Persians at the Battle of Plataea, construction of the walls began almost immediately in c. 475 BCE. The Spartans argued that the fortifications would make the perfect base for future invasions. They proclaimed themselves against the walls’ construction; however, the real reason was almost certainly the Spartans’ growing sense of unease over Athens’ regional dominance. The walls, built on top of the remains of the old city walls, connected the harbour of Piraeus to Athens and sealed the city off from the rest of the mainland, effectively making Athens an ‘island’. The Spartans, angered by the walls’ construction, launched the first of the Peloponnesian Wars in protest c. 460 BCE.