|Take a trip into the past|
The Prince that was Promised is a common phrase referring to some chosen prince or leader that will rise up and conquer the world or even save it from eternal darkness. There have been a range of theories as to who this Chosen Prince is but I think it's not just one prince but 2: Jon Snow and Daenerys Targaryen. Now I haven't read the books so forgive me if I get things wrong. Mostly I'm drawing from the show.
|The Stallion who mounts the world|
Every culture from Westeros to Essos seems to have some prophecy about a mythical Chosen One. Daenerys is definitely the Stallion that Mounts the World:
"As swift as the wind he rides, and behind him his khalasar covers the earth, men without number, with arakhs shining in their hands like blades of razor grass. Fierce as a storm this prince will be. His enemies will tremble before him, and their wives will weep tears of blood and rend their flesh in grief. The bells in his hair will sing his coming, and the milk men in the stone tents will fear his name. The prince is riding, and he shall be the stallion who mounts the world."
"As swift as the wind he rides" and "Fierce as a storm". Daenerys is mostly called Daenerys Stormborn before any of her other titles and dragons can be pretty swift. Although Dothraki worship the horse the prophecy isn't specific on what sort of mount this Stallion will ride. After the last episode where Dany gave this inspiring speech about conquering Westeros reminds me of the last part of the prophecy: "the milk men in the stone tents will fear his name." Milk men? Stone tents? Doesn't take a genius to figure that this refers to the men of Westeros living in castles. Yes, the prophecy describes a prince and Dany is a woman but remember in this world as well as in ours it's mostly a patriarchal society where men are on top.
"There will come a day after a long summer when the stars bleed and the cold breath of darkness falls heavy on the world. In this dread hour a warrior shall draw from the fire a burning sword. And that sword shall be Lightbringer, the Red Sword of Heroes, and he who clasps it shall be Azor Ahai come again, and the darkness shall flee before him."
"When the red star bleeds and the darkness gathers, Azor Ahai shall be born again amidst smoke and salt."
I'm never one to take prophecies as black and white. They're never literal. A sword is never a sword. Leading me to believe this so called Lightbringer is Jon Snow. For that I give you the vows spoken by the Men of the Night's Watch:
"Night gathers, and now my watch begins. It shall not end until my death... I am the sword in the darkness... I am the fire that burns against the cold, the light that brings the dawn, the horn that wakes the sleepers, the shield that guards the realms of men."
|Born amidst Smoke and Salt|
Seems to fit so well doesn't it? And Azor Ahai being "born again amidst smoke and salt"? Jon Snow was brought back from the dead by Melisandre (smoke as in smoke and fire) and Ser Davos Seaworth (salt as in the sea). Jon is a light bringer not in a literal sense but warrior archetypes are often identified with weapons like being called a hammer or a shield. So it's most likely that Jon is this sword, Lightbringer but does that also make him Azor Ahai? Maybe... Azor Ahai wields Lightbringer so it may just be Jon will work with someone against the Others and the Night King. Dany maybe? Or even Bran? Bran is a warg that can possess humans as well as animals. It could very well be that Bran is Azor Ahai and Jon Snow will be his sword.
|One of the Chosen Ones|
Not sure if I'm the only one who's made these connections or put forth these theories but prophecies are so poetic and cryptic that you don't know what they mean until after everything has gone to hell and even then you're skeptical. Also prophecies can be interpreted a thousand different ways so it's best to avoid them altogether if you can help it. One thing is for sure: the world is approaching a war between light and darkness. The end will determine the fate of not only Westeros but the world.