On 24 December 1951 Idris announced the establishment of the United Kingdom of Libya from the al-Manar Palace in Benghazi.
The country had a population of approximately one million, the majority of whom were Arabs, but with Berber, Tebu, Sephardi Jewish, Greek, Turkish, and Italian minorities.
The newly established state faced serious problems; in 1951, Libya was one of the world's poorest countries.
Much of its infrastructure had been destroyed by war, it had very little trade and high unemployment, and both a 40% infant mortality rate and a 94% illiteracy rate.
Only 1% of Libya's land mass was arable, with another 3–4% being used for pastoral farming.
Although the three provinces had been united, they shared little common aspiration.

The Kingdom was established along federal lines, something that Cyrenaica and Fezzan had insisted upon, fearing that they would otherwise be dominated by Tripolitania, where two-thirds of the Libyan population lived.
Conversely, the Tripolitanians had largely favoured a unitary state, believing that it would allow the government to act more effectively in the national interest and fearing that a federal system would result in further British and French domination of Libya.
The three provinces had their own legislative authorities; while that of Fezzan was composed entirely of elected officials, those of Cyrenaica and Tripolitania contained a mix of elected and non-elected representatives.
This constitutional framework left Libya with a weak central government and strong provincial autonomy.
The governments of successive Prime Ministers tried to push through economic policies but found them hampered by the differing provinces.
There remained a persistent distrust between Cyrenaica and Tripolitania.
Benghazi and Tripoli were appointed as joint capital cities, with the country's parliament moving between the two.
The city of Bayda also became a de facto summer capital as Idris moved there.

According to the reporter Jonathan Bearman, King Idris was "nominally a constitutional monarch" but in practice was "a spiritual leader with autocratic temporal power", with Libya being a "monarchical dictatorship" rather than a constitutional monarchy or parliamentary democracy.
The new constitution granted Idris significant personal power, and he remained a crucial player in the country's political system.
Idris ruled via a palace cabinet, namely his royal diwan, which contained a chef de cabinet, two deputies, and senior advisers.
This diwan worked in consultation with the federal government to determine the policies of the Libyan state.

 King Idris was a self-effacing devout Muslim, he refused to allow his portrait to be featured on Libyan currency and also insisted that nothing should be named after him except the Tripoli Idris Airport.
Idris' regime soon banned political parties from operating in the country, claiming that they exacerbated internal stability.
From 1952 onward, all candidates for election were government nominees.
In 1954, the Prime Minister Mustafa Ben Halim suggested that Libya be converted from a federal to a unitary system and that Idris be proclaimed President for Life.
Idris recognised that this would deal with the problems caused by federalism and would put a stop to the intrigues among the Senussi family surrounding his succession.
He asked Ben Halim to produce a formal draft for these plans, but the idea was dropped amid opposition from Cyrenaican tribal chiefs.

Under King Idris, Libya found itself within the Western sphere of influence.
It became the recipient of Western expertise and aid, and by the end of 1959 it had received over $100 million of aid from the United States, being the single biggest per capita recipient of American aid.
U.S. companies would also play a leading role in the development of the Libyan oil industry.
This support was provided on a quid pro quo basis, and in return Libya granted the United States and United Kingdom usage of the Wheelus Air Base and the al-Adem Air Base.
This reliance on the Western nations placed Libya at odds with the growing Arab
On 24 December 1951 Idris announced the establishment of the United Kingdom of Libya from the al-Manar Palace in Benghazi. The country had a population of approximately one million, the majority of whom were Arabs, but with Berber, Tebu, Sephardi Jewish, Greek, Turkish, and Italian minorities. The newly established state faced serious problems; in 1951, Libya was one of the world's poorest countries. Much of its infrastructure had been destroyed by war, it had very little trade and high unemployment, and both a 40% infant mortality rate and a 94% illiteracy rate. Only 1% of Libya's land mass was arable, with another 3–4% being used for pastoral farming. Although the three provinces had been united, they shared little common aspiration.
The Kingdom was established along federal lines, something that Cyrenaica and Fezzan had insisted upon, fearing that they would otherwise be dominated by Tripolitania, where two-thirds of the Libyan population lived. Conversely, the Tripolitanians had largely favoured a unitary state, believing that it would allow the government to act more effectively in the national interest and fearing that a federal system would result in further British and French domination of Libya. The three provinces had their own legislative authorities; while that of Fezzan was composed entirely of elected officials, those of Cyrenaica and Tripolitania contained a mix of elected and non-elected representatives. This constitutional framework left Libya with a weak central government and strong provincial autonomy. The governments of successive Prime Ministers tried to push through economic policies but found them hampered by the differing provinces. There remained a persistent distrust between Cyrenaica and Tripolitania. Benghazi and Tripoli were appointed as joint capital cities, with the country's parliament moving between the two. The city of Bayda also became a de facto summer capital as Idris moved there.
According to the reporter Jonathan Bearman, King Idris was "nominally a constitutional monarch" but in practice was "a spiritual leader with autocratic temporal power", with Libya being a "monarchical dictatorship" rather than a constitutional monarchy or parliamentary democracy. The new constitution granted Idris significant personal power, and he remained a crucial player in the country's political system. Idris ruled via a palace cabinet, namely his royal diwan, which contained a chef de cabinet, two deputies, and senior advisers. This diwan worked in consultation with the federal government to determine the policies of the Libyan state.
 King Idris was a self-effacing devout Muslim, he refused to allow his portrait to be featured on Libyan currency and also insisted that nothing should be named after him except the Tripoli Idris Airport. Idris' regime soon banned political parties from operating in the country, claiming that they exacerbated internal stability. From 1952 onward, all candidates for election were government nominees. In 1954, the Prime Minister Mustafa Ben Halim suggested that Libya be converted from a federal to a unitary system and that Idris be proclaimed President for Life. Idris recognised that this would deal with the problems caused by federalism and would put a stop to the intrigues among the Senussi family surrounding his succession. He asked Ben Halim to produce a formal draft for these plans, but the idea was dropped amid opposition from Cyrenaican tribal chiefs.
Under King Idris, Libya found itself within the Western sphere of influence. It became the recipient of Western expertise and aid, and by the end of 1959 it had received over $100 million of aid from the United States, being the single biggest per capita recipient of American aid. U.S. companies would also play a leading role in the development of the Libyan oil industry. This support was provided on a quid pro quo basis, and in return Libya granted the United States and United Kingdom usage of the Wheelus Air Base and the al-Adem Air Base. This reliance on the Western nations placed Libya at odds with the growing Arab
Idris of Libya