After more extensive research, we can conclude that there was an advanced ancient civilization that dominated the galaxy around forty thousand years before the Battle of Yavin. Even before the Celestials. Unfortunately, we know extremely little of this government.
—Historical Council, c. 57 ABY
The Galactic Kingdom, also called the Kingdom of the Galaxy, and later the Old Kingdom, was a galactic government that emerged from the Deep Core and the Core Worlds, eventually dominating the galaxy. Formed after the Declaration of Domination, signed during the Great Unification in 41,863 BBY, the Kingdom went on to annex and invade most the known galaxy. The signers of the Declaration where member worlds of the Core Coalition, a unified faction of Core World and Deep Core governments. They believed that, being the most advanced societies of their time, it gave the, the right to invade others. The Kingdom embarked on a War of Conquest soon after the Declaration, invading the Inner Rim Territories and Mid Rim after taking control of the remaining Colonies.
Ruled by the royal family, the Kingdom was officially a constitutional monarchy under it's first ruler, Galactic King Contispex I. However, in reality, it was an absolute monarchy under direct control of the King. The legislature, which was not much more than an advisory body, simply there to make the government appear democratic, was the Council of Regional Governors. They officially were the leadership of the Kingdom up until 41,855 BBY, when King Contispex I declared himself the absolute monarch, something which much of the populace already knew to be the case. The Council remained as a group of bureaucrats that acted as advisors, and of course, their original role of Regional Governors. In 41,855 BBY, the King also created the position of Territorial Governor, which ruled several oversectors and held more power than Regional Governors.
At an unknown date before