Much of the region came under the rule of members of the Bagratuni Dynasty in the 9th and 10th centuries, when it was still a vassal of the Roman Empire. The two major states of Armenia and Kartli became independent in the mid-9th century, forming a strong alliance so as to keep all the Bagratid lands within the family. Armenia eventually achieved hegemony over the Caucasus and Armenian Bagratids came to rule in a vast swath of land stretching from Circassia to Persia.
Many of the eastern lands were lost following the Mongol invasion and the 1255 Battle of Arbela, and Bagratid supremacy was afterwards supplanted by the Mehranids. Though forced to recognise the overlordship of their newly powerful neighbours, the Bagratid kings of Kartli and Armenia remained strong and retained a high degree of autonomy. This lasted until 1712 in Armenia, when the royal family was deposed by the Peshdadid Shah and exiled to Ferghana, and 1753 in Kartli when the Peshdadids and the Lithuanian-Polish-Russian Commonwealth agreed to divide the country between them.
Both countries recovered their independence in the late 19th century after the First World War. As they were still surrounded by powerful enemies, and as the two had long shared close cultural and political ties, it was decided to form a formal union to strengthen them both. Thus, at the 1862 Gori Conference and with the passage of the Treaty of Gori, the Federal Republic was formed.
Caucasia consists of two equal parts, Armenia and Kartli, each of which has its own laws, language and customs. The two have separate legal systems and constitutions, and both retain the right to unilaterally separate from the other. They share however a common currency, a military service and a single internal market, and have a common federal government whose main duties are concerned with the maintenance of the state and its representation abroad.
Federal governance relies on a parliamentary system. Parliament is bicameral - the lower house consists of 400 members, of which 200 each are elected by the people of each part of the country. The upper house consists of 100 members, with each sub-national government appointing 30 and the remaining 40 being elected by the lower house. The President is chosen by the upper house and the Prime Minister by the lower - customarily the posts are divided between the two communities, alternating after each election. For example, the current Prime Minister Tamar Khalvashi is Kartvelian, while her predecessor Khosrov Margaryan was Armenian. The President, though head of state, is mainly a ceremonial figurehead, with governmental policy being decided by the Prime Minister and the Cabinet.
Currently the largest parties in the lower house are the Social Democrats (including both its Armenian and Kartvelian branches), the Federalists, and the Adjaran Nationalist Party. The latter two are currently part of a coalition government.