The Original Seven Kingdoms Flag of Game of Thrones

There are many kingdoms within the Game of Thrones cable television series on HBO.  But note, the dominant religion is held in the Faith of the Seven.  Seven also refers to the Seven Kingdoms, when Westeros was divided into seven kingdoms and then conquered by House Targaryen by the Sir Aegon Targaryen. 

Here is a flag that represents the Original Seven Kingdoms that became united as one under House Targaryen.

Starting the in the upper left hand corner, which is the canton, we have the seven pointed star that is reflective of the Faith of the Seven.  It is analogous to the cross of England that all Kingdoms heed in some fashion.  But for the Religion of Seven, there are seven models that represent humanity in this universe.  

To the right is a blue region that has a circle, a crescent moon and falcon that represents House Arryn which rules over the Kingdom of the Mountain & Vale.

Next over to the right is the Dire wolf's head on white.  This sigil represents the House of Stark which rules the Kingdom of the North.

Further right is the lion of the house Lannister on a field of red.  The Lannister House rules over The Kingdom of the Rock.

Below the Lion of Lannister is a stag on a field of yellow with a crown around its neck.  This sigil represents the House of Durrandon which eventually mixed and became House Baratheon.  This area is the Kingdom of the Stormlands.

To the left is a chained saltire with four different emblems of the House Hoare, which is a House no more.  The four emblems being a longship, grapes, a pine, and a raven.  The ancient Kingdom was the Isle and the Rivers.  This Kingdom is split.  The Isles are under the House Ironborn while the mainland is under House Tully.  House Ironborn has a yellow squid upon black, while House Tully has a trout leaping in the air coloured red above a river. 

Further left is the sigil of a green hand on white that represents the extinct House of Gardener.  Instead of the 'green thumb' they have a green hand to denote farming expertise.  This is the Kingdom of the Reach which is now split.  House Tyrell occupies part and the other half is directly ruled by the Iron Throne, kinda' like Washington DC being under the seat of the King, oops I meant federal government,
better known as the Iron Throne.

Finally in the lower left corner is the sigil of House Martell which as the Sun pierced by a spear.  This is the Kingdom Dorne, usually referred as a Principality, yet a Kingdom nonetheless. 

This great work of fiction takes a lot of hints from the ancient English history when England was divided into Seven Kingdoms.  You can see the flag below crossed with the Iron Throne Kingdoms of HBO.  Starting from the lower left corner the authentic seven kingdoms were: Mercia (yellow X on blue), Northumbria (yellow and red, vertical stripes), Sussex (the six birds on blue), Kent (white horse on red).  Then on the upper part we have: Essex (3 swords on red), East Anglia (3 crowns on blue), Wessex (the yellow dragon on red).  Finally in the canton is the religious symbol and icon for all original seven Kingdoms that became England (red cross on a white field).