When Xerxes asked King Leonidas or Sparta to lay down his Arms at Thermopylae, despite having only 300 of Spartas' most elite warriors compared to many times that number in the Persian Army (modern estimates peg the Persians in the 200,000 soldier range), Leonidas responded, in greek, "Molon Labe" which means "come and get them". They subsequently fought to the death and delayed the Persian advance long enough to totally demoralize the Persian army.
The fierce resistance of the Spartan-led army offered Athens the invaluable time to prepare for a decisive naval battle that would come to determine the outcome of the war. The subsequent Greek victory at the Battle of Salamis left much of the Persian Empire's navy destroyed and Xerxes was forced to retreat back to Asia, leaving his army in Greece under Mardonius, who was to meet the Greeks in battle one last time. The Spartans assembled at full strength and led a pan-Greek army that defeated the Persians decisively at the Battle of Plataea, ending the Greco-Persian War and with it the expansion of the Persian Empire into Europe.
In modern use, it has been a rallying cry for gun owners opposed to excessive gun control. Kinda like "from my cold dead hands".
