The city of Constantinople had always attached itself to the image of the Virgin Mary. She was seen as a figure that could protect them from enemy armies. One particular time that she was pivotal to the city’s defense was during the siege of Constantinople in 626 to 627. It was during the reign of the Emperor Heraclius and he was just starting to launch a counter offensive against the invading Sassanid armies. Suddenly, a large horde of Avars approached the city along with a large fleet of Sassasnid ships. It said that the patriarch of the Roman church at the time, Patriarch Sergius prayed all night without even sitting down to rest. Apparently, the prayers worked when a huge storm sent tidal waves into the Sassasnid ships, causing much damage to the combat effectiveness of the besiegers. Eventually, the Avars retreated from the city as well, allowing for Heraclius to continue his counter offensive against the invaders.
The prayers that were made by Patriarch Sergius were eventually called the Akathist Hymn. It was called Akathist because the word in Greek, Akathistos, means not seated. The Hymn was originally only used in Eastern Orthodox settings but has spread to other Christian settings. The Akathist Hymn is representative of the desires that humans have to invoke the divine in extraordinary settings, especially during war. Humans yearn for a certain degree of sacredness to their lives, and this song best represents the human condition and his relationship with the god and the spirits.
The Akathist Hymn: A Lyric Poem of Unparalleled Beauty (greekreporter.com)
Byzantine-Empire.com 