The battle of Thermopylae was fought between 7000 Greeks under Leonidas (including 300 Spartans) and 500,000-2.5 million Persian troops under Xerxes. Xerxes had marched across the Hellespont towards Greece because he wanted Greece to become a satrapy of his and submit to his divine will by giving him earth and water. The two armies met at a 50-foot-wide pass in Northern Greece and here, a small phalanx of Greek hoplites held off wave after wave of Persian infantrymen, cavalrymen, and Immortals. The Spartans demonstrated their bravery again and again, and their lifelong devotion to military training proved to pay off.

Eventually, Ephialtes (a Greek traitor) led the Persians around the pass to the rear of the Greek defenders. Surrounded, the Spartans and Thespians were killed by a volley of arrows. Leonidas, himself, looked forward to dying because the oracle at Delphi prophesized that his death would save Sparta.

For more information:
300 (Movie)
http://www.iranchamber.com/history/articles/persian_wars5.php
Histories by Herodotus
http://www.greektexts.com/library/Herodotus/Polymnia/eng/242.html
Extreme War by Terrence Poulos
Military Anecdotes by Max Hastings
Military History Magazine (January 2006): Spartan Stand at Thermopylae

Military History Podcast is sponsored by Armchair General Magazine and the International Research and Publishing Corporation

The Hashshashins (where we get our word "assassins") were active during the Abbasid Era of the Arab Period of Hegemony within the Islamic Period of Hegemony. The Hashshashins were Nizari Ismaili Shiite Muslims. They were led by Hassan-i-Sabah who, through the use of hashish, gave his recruits the impression that he was God and he wanted them to do his will. Until the coming of the Mongols under Hulagu Khan, the Hashshashins were very good at their job and they assassinated many high-profile people.

Though they are one of the most famous assassin groups, they are by no means the only ones. Others include Al Qaeda, the Mafia, the Black Hand, the IRA. The CIA, for example, is reported to have made 638 attempts to remove Castro from power.

For more information, read:
Military History Magazine (October 2002): Perspectives
Islamicity.com
Al Qaeda Training Manual
Quran
638 Ways to Kill Castro

Military History Podcast is sponsored by Armchair General Magazine and the International Research and Publishing Corporation

The Knights Templar was a Christian military order founded during the Crusades in order to protect Christian pilgrims traveling to the Holy Land.  These "Monks of War" were highly disciplined and they participated at many major battles during all nine Crusades, including the pivotal Battle of Hattin.  They also founded the first modern checking/credit system, which made the organization wealthy enough to buy the island of Cyprus. 

The Templars were exempt from all laws (except those given by the Pope) and as a result, they were feared by the kings of Europe.  One king, Philip the Fair, decided to deal with the problem and on Friday the 13th, he simultaneously betrayed and backstabbed all of the Templars.  The Templars then disappeared from history, though many groups (such as the Freemasons), have claimed that they are extensions of this famous organization.

For more information, read:
http://www.sacred-texts.com/sro/hkt/index.htm
http://www.newadvent.org/cathen/14493a.htm
http://www.templarhistory.com/index.html
http://www.slate.com/id/2140307/?nav=tap3
Worlds Together, Worlds Apart

Military History Podcast is sponsored by the International Research and Publishing Corporation and Armchair General Magazine