Earth Kingdom

The Earth Kingdom is one of the world's nations of the Avatar Timeline. Spanning an entire continent as well as several subsidiary islands, it is the largest and most populated sovereignty in the world and encompasses much of the eastern hemisphere. The kingdom was originally operated as a monarchy under the rule of a king or queen, but the 54th Earth King, Wu of the Hou-Ting Dynasty, announced his intention to abdicate the throne in favor of splitting the nation into independent states with democratically elected leaders, akin to the political system used in the United Republic of Nations.

The people of the Earth Kingdom are proud and strong and adhere to a philosophy of peaceful coexistence and cooperation with the other nations of the world. Earthbenders use their abilities for defense and industry and fiercely defended their cities against Fire Nation attacks during the Hundred Year War. It also has a large economy based on agriculture and limited industry, though it is not as economically powerful as the Fire Nation, which benefits from advanced technology.

The Earth Kingdom is characterized by significant ethnic and cultural diversity, a consequence of the country's vast territorial expanse. As a result, it suffers from high levels of local autonomy and ethnic conflict, both of which began accelerating as the central government grew weak. Despite this division, the people's recognition of the Earth Kingdom as a single political entity is largely strengthened through the communal belief in a shared history and identity.

The Earth Kingdom long withstood encroachments on their borders in the Fire Nation's century-long imperialist war. Other than the Avatar, the Earth Kingdom was the only real obstacle that hindered the Fire Nation from achieving world domination. Though the Water Tribe aided the Earth Kingdom in the War, the conflict progressed poorly and took a heavy toll on them as the years passed.

In Mega Man ZX Shippuden, however, the kingdom was operated by the Galactic Eggman Empire during Dr. Paul Robotnik's rise to power.

Raava Period
In the era of Raava, most of the later Earth Kingdom was part of the Spirit Wilds, and its people were forced to survive the wrath of spirits and the untamed nature. The predecessors of the Earth Kingdom found several ways to survive these hardships: Some retreated into cities built atop lion turtles. They received the element of earth from these sentient beings that granted the bending art through energybending. The humans could request the ability whenever they ventured into the Spirit Wilds, to aid in the gathering of food and resources.[17] Others chose a nomadic lifestyle, traveling the wilds and staying at one place only as long as they could. One particular tribe of nomads, however, was able to built a permanent city under the guardianship of the spirit Lady Tienhai in what would become the western Earth Kingdom. Several aspects of life and observances practiced by the predecessors of the first citizens of the Earth Kingdom later became part of the nation's shared culture, notably in the creation of fortified strongholds constructed out of earth, akin to the structures seen in lion turtle cities populated by early Earth Kingdom citizens.

After Avatar Wan closed the spirit portals and most spirits left the mortal world, the lion turtles renounced their roles as protectors of mankind. At this point, the predecessors of the Earth Kingdom left the lion turtle cities in favor of establishing settlements throughout the mainland, while most of the nomads settled down. Soon after, the ancestors of the first Earth Kingdom citizens began to wage wars, inventing the large earth coins as primary weapons for their earthbender warriors to use. Avatar Wan died after intervening in a battle of Earth Kingdom predecessors.

Over time, the kings of Ba Sing Se became increasingly powerful and began to unite and subjugate the numerous kingdoms and peoples of the later Earth Kingdom. They left some kings and nobles in power, however, as long as they submitted to Ba Sing Se. Eventually, one king of Ba Sing Se ended the unification wars in victory and crowned himself the first Earth King, not to leave his capital city until his death.[25] Despite Ba Sing Se's victory, the earth monarchs were unable to establish a centralist or authoritarian regime due to the kingdom's sheer size. As result, the Earth Kingdom became a confederate monarchy, divided into several semi-autonomous provinces. Over time, the power of the Earth monarchs would wax and wane, but none of them would truly control all of the kingdom. Some regions, like the Si Wong Desert were too remote and difficult to govern, whereas others were simply too unimportant for the central government to care about them. The government's inability to exercise full control allowed outlaw groups to become unusually sophisticated in the Earth Kingdom: They developed their own culture and code of conduct, and became known as daofei. Despite this, the Earth monarchs usually held absolute power in Ba Sing Se.

Eggman Imperial Era
During the Rise of the Galactic Eggman Empire, the Fire Lord Sozin and the other earth monarchs agreed to let the Emperor of the Multiverse, Paul Eggman to have total control over the Fire Nation, Earth Kingdom, Water Tribes and Nomads through fear and intimidation. With Eggman controlling the cities and resource-rich areas, Eggman has the Egg Fleet, the Eggman army and the badniks turning the most of the west and northwest into a location that the empire may build the armies and a armada of warships as their fortified fortress due to Eggman seizing power over the Mushroom Kingdom.