It would help if you have seen the movie before.
Long ago, in days of old, there once was the kingdom of Sparta, home of the greatest warriors in the world.

One day, a Persian messenger arrived on really slow horses, so slow they were practically in slow-motion. The messenger sought the ruler of Sparta, King Letightanus to bear a message from Emperor Jerkxes.

“Earth and water”
“I beg your pardon?” raised the king.
“Emperor Jerkxes, ruler of the world, asks you to join his kingdom. If you don’t submit, the consequences will be dire.”
“Submit?” the king draws his sword. “Sparta will never submit! Out economy is mainly based on tourism. Have you seen our Italian food?”
“Jerkxes has control over plentiful Chinese food that can overwhelm you! This is madness!
“Madness? THIS IS PASTA!!” bellowed the king before he kicks the messenger into a half-built bottomless pit.

Momentarily the king realized an impending attack from the Persian hordes.

“Oh, crap.”

That night, King Letightanus couldn’t sleep.

“Man, I’m in real trouble bigtime.”
“Those Persians cannot challenge us, Sparta is the home of real men, it says so on the brochure,” said his wife, Gorgozola.
“But I’m gonna miss our son’s circumcision tomorrow…” the king whined.
“You’re such a wimp! That’s it, I’m breaking up with you.”
“Oh well, at least I have the bathroom all to myself…”

The next morning, the king assembled 300 of his finest men, ready to counter the Persian attacks. The Spartan councilmen, who did not approve of the war, approached the king outside the gates.

“What is the meaning of this?”
“Oh, I’m just going up the hill for my regular yoga exercise, and these are just my spectators.”

The 300 warriors were ready in full gear, awaiting orders.

“This red cape is totally giving me the rashes..”
“Dude, have you been working out?”
“Ouch! Something poked me! Put away that spear!”
“That was not a spear…”

And on the marched to the battlefield to engage the Persian army. Halfway the journey, Captain Lateforbus realized something.

“Wait a minute, if the Persian messengers are stuck in the half-built bottomless pit, how would Jerkxes know about our defiance?”

“Oh yeah…” muttered the king.

“Maybe they have international roaming…” said Notsotightanus.

Sure enough, the Persian legions arrived in style. The might Spartan 300 battled and survived foes of all kinds: beasts, ninjas, mad Mexican midgets, American military (who retreated when told that Sparta has no oil), and eventually Emperor Jerkxes himself, along with his elite guard.

Before the battle rest of the battle ensued, the two rulers had a chat.

“Like, omigosh. Give up already! You can’t defeat us, hello! Earth to Sparta!”
“We’re not giving up our Italian food, not now, not ever.”
“Okay, how about if I offer you stuff, hmm? These piercings of mine are not just for show, you know.”
“Sorry, no bargain.”
“Fine, then. We’ll see who wins this war. Hmph!”

Returning to his men, the king has hopelessness written all over his face.

“Oh boy, we’re screwed this time.”
“But sire, we’re Spartans! We can defeat anyone!”
“I’m afraid we’re steeply outnumbered. I’m going to send Faramir back to Sparta to pep-talk the dudes to send us reinforcements.”
“Yes, my king. I shall hurry.”

And off, Faramir went to get help from the rest of the mighty Spartan army.

“Do you think they’ll come in time?” asked Notsotightanus.
“I… don’t think so.” said Captain Lateforbus upon seeing the million Persian soldiers who will arrive momentarily.

“Ah, dangit” muttered the King.