This thread is meant as a discussion platform where we put our worldbuilding skills together to flesh out the Kingdom of Astjumreva. So please join in for this worldbuilding discussion. I will use this post further to elaborate on the ideas I have for this NPN Kingdom and all are open for discussion.

The Kingdom of Astjumreva
The Kingdom of Astjumreva is a prominent nation in Terra Aurora's southern continent. Roughly 500 Toors in length and 100 wide, shows that the Kingdom is amongst the larger nations. To the north it's bordered by the Great Ocean. To the south by the Red Mountains and the Darkwood Forest. To the east by the Scarlet Hills and to the west by the Olean Holt and the Adamantian Mountains where the Kingdom of Threnebor lays. This Kingdom is a shining beacon of prosperity and commerce on the southern continent. While it maintains a fairly isolationist policy, it aims to improve the lives of its citizens on all fronts. Economy, religion, magic, ... You name it. As its foundation, the Kingdom has the Grand Charter. The Grand Charter serves as a constitution which protects the rights of all Astjumrevan citizens whatever caste they may belong to. This quest for prosperity and their new way of peace is symbolized in their banner. The blue signifies the Great Ocean across which they trade with many nations. The yellow represents the flourishing agriculture of the nation. The three red towers have a special meaning for the Astjumrevans. The two outer towers represent the old Kingdoms of Astjum and Reva. The tower in the middle represents their synthesis and stand for their new way of life towards peace and prosperity.
 

History
Long ago in a time long forgotten were the two Kingdoms of Astjum and Reva. These Kingdoms were ruled over by man and as so often with man, they inevitable turn to squabble with one another. For centuries these two Kingdoms fought across the Red Mountains which now splits the nation in half. The reasons for these conflict have been lost to time. Some archives mention wars over women, resources and territory. Even wizardry was used to combat between each other. Man even suppressed other intelligent beings and used them in slavery in these dark times. This all came to change when the King of Astjum, Adalbert, asked the then widowed Queen of Reva, Sturina, to marry him. This was a surprise for all and while the transition wasn't easy, but eventually the two Kingdoms merged and formed the Kingdom of Astjumreva. This was possible due to the many reforms in both Kingdoms. As citizens saw the benefit of trade and peace, they grew to appreciate the fruits of the joint labour. With this intermarriage between the two nations exploded and the two ethnicities mixed so much, that no pure Astjuman or Revan exists to this day. 

Feudal System
To administrate the Kingdom, a feudal system is in place that helps the monarch govern. Each title has their own responsibilities and duties. Each rank is subservient to the previous high rank who appoints them. They are to protect their minions and if called upon by the High King, to march to battle and mobilize the peasants. They also have to pay tribute which can be paid for in money or goods.

High King
The highest noble rank of the Kingdom. Serves as the head of state and governs the entire Kingdom. Together with his Royal Cabinet and the Council of Magic, he makes laws concerning the entire Kingdom and appoints the Dukes and Duchesses.

Archduke/Archduchess
The heir to the throne. Another title for Crown Prince and governs of the Archduchy of Tok-Il where he need to prove that he is able to protect the border and thus the Kingdom in the future.

Duke/Duchess
Highest noble rank. In total 36 of them which are all part of the House of Lords which is another advisory council for the High King. They report directly to the High King and are his extended group of friends. Most of these families will also try to marry with the royal family to increase their standing with them.

Marquis/Marchioness
An intermediary noble rank that govern of a Marquisate. Mostly a hereditary title.

Count/Countess
The lowest noble rank which may request the attention of the high King. Governs over a County and is hereditary.

Viscount/Viscountess
Normally the most befriended among the Barons beneath the Count. Serves as the right hand of the Count. Governs over a Barony and is appointed by the Viscount. In times of peril he may even take over the County if his Count is rendered unavailable.

Baron/Baroness
Smallest noble rank that governs over a Barony. Usually gained by hereditary means or a promotion from Knight bestowed upon by the Viscount.

Knight/Dame
A professional soldier that is responsible for the protection of land. His land plots are fairly small and part of the Baron's land who he has been gifted. These lands are too small however to have any real administration, but the peasants under his protection gave him small tribute for their protection. The Knight also has access to robust armour which lower peasant can't afford.

Esquire
The apprentice of a Knight and possible heir.

Magic
Magic is practiced in the Kingdom, but under supervision by the Council of Magic. The Council of Magic consists of the five most elderly wizards across the Kingdom and also serve as an advisory council to the High King. Together they make the rules of Magic for the Kingdom and all of it is written in the Codex Sturina as the Mythical Queen was a sorceress herself. In all other matters, magic is fairly decentralized and most wizards go about their own business to help Astjumrevans.

Geography
In the Great Ocean, not too far from the Astjumrevan coast, lays the Neeton Reef Barrier. This natural wonder is filled with corals of all colours and its resources are a major financial boost the the Kingdom. 
The two main rivers are the Kermdal and Relba river. The Kermdal River is a long river coming from the southern country all the way to the Great Ocean. This river serves as a major shipping and transportation line of the region of the old Kingdom of Astjum. In the same manner the Relba river splits the former Kingdom of Reva in two. To the south of it lay the Scarlet Hills which are hills filled with red grasses which are said to be medicinal when smoked. This has become a major export of the Kingdom as well.
To the west is the Olean Holt which is filled with olive and grape vine woods. Olive oil and wine are famed in the Astjumrevan cuisine and most of them have their origins in the Olean Holt.
Greenwood and Darkwood forest are the major forest of the Kingdom and also where most of the wood is gained.
Lastly the Red Mountains were the border between the two ancient Kingdoms and gain their name due to a red mineral that colours most of the stones red. Legends tell that this actually is the blood of the ancient giants which were formed into rocks. A type of red marble is also mined her and most palaces in the Kingdom are build with this red marble stone.