A prime minister, also known as a chief of cabinet, chief minister, first minister, minister-president or premier, is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. A prime minister is not the head of state, but rather the head of government, serving as the chief of the executive under either a monarch or a president in a republican form of government.
In parliamentary systems of government (be they constitutional monarchies or parliamentary republics), the Prime Minister (or occasionally a similar post with a different title, such as the Chancellor of Germany) is the most powerful politician and the functional leader of the state, by virtue of commanding the confidence of the legislature. The head of state is typically a ceremonial officer, though they may exercise reserve powers to check the Prime Minister in unusual situations.
Under some presidential systems, such as South Korea and Peru, the prime minister is the leader or the most senior member of the cabinet, but not the head of government. As such, in South Korea, the prime minister is equivalent to that of a vice president which is the second in-command and assumes the presidency in the absence of the president.
In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime minister is the presiding member and chairman of the cabinet. In a minority of systems, notably in semi-presidential systems, a prime minister is the official appointed to manage the civil service and execute the directives of the head of state.
Today, the prime minister is often, but not always, a member of the legislature or its lower house, and is expected with other ministers to ensure the passage of bills through the legislature. In some monarchies the monarch may also exercise executive powers (known as the royal prerogative) without the approval of parliament.
As well as being head of government, being prime minister may require holding other roles or posts—the prime minister of the United Kingdom, for example, is also First Lord of the Treasury and Minister for the Civil Service. In some cases, prime ministers may choose to hold additional ministerial posts (e.g. when the portfolio is critical to that government's mandate): during the Second World War Winston Churchill was also Minister of Defence (although there was then no Ministry of Defence). Another example is the Thirty-fourth government of Israel (2015–2019), when Benjamin Netanyahu at one point served as the prime minister and minister of Communications, Foreign Affairs, Regional Cooperation, Economy, Defense and Interior.
The term "prime minister" is attested in 17th century sources referring to Cardinal Richelieu, after he was named premier ministre to head the French royal council in 1624. The title was used alongside the principal ministre d'État ("chief minister of the state") more as a job description. After 1661, Louis XIV and his descendants refused to allow one of their Ministers to be more important than the others, so the term was no longer in use.
In the 18th century in the United Kingdom, members of parliament disparagingly used the title in reference to Sir Robert Walpole (whose official title was First Lord of the Treasury). During the whole of the 18th century, Britain was involved in a prolonged conflict with France, periodically bursting into all-out war, and Britons took outspoken pride in their "Liberty" as contrasted to the "Tyranny" of French Absolute Monarchy; therefore, being implicitly compared with Richelieu was no compliment to Walpole. Over time, however, the title became honorific and remains so in the 21st century.
The position of a head of government separate from the head of state, or as the most important government administrator or minister after the monarch in rank developed in multiple countries separate from each other. The names given could be "prime minister", although other terms were also used such as "chief minister", "grand chancellor", "chancellor", "grand vizier", "counselor", and others.
The literal title itself can be traced back to the Abbasid caliphate and the Ottoman Empire. They both had an official title of Grand Vizier simply the Head of the Government which is called Prime Minister nowadays. The Grand Vizier was the most powerful person after sultan but sometimes the Grand Vizier of Ottoman Empire was more powerful than sultan himself. The position of Chancellor is the same or comparable in some countries as a prime minister, even if the label is different. The term goes back to ancient Roman times as head of the chancellery. This title as head of government or the administration existed in ancient China as Grand Chancellor (Chinese: 宰相; pinyin: Zǎixiàng), sometimes translated as "prime minister", existed since 685 BCE and ancient Japan Chancellor of the Realm (太政大臣 Daijō-daijin) since the 7th century CE. In the Holy Roman Empire the position of Archchancellor was the highest dignitary and traces to 860 CE, out of which later derived the positions of head of government such as the modern Chancellor of Germany, who is head of the federal government and an executive prime minister.
The power of these ministers depended entirely on the personal favour of the monarch. Although managing the parliament was among the necessary skills of holding high office, they did not depend on a parliamentary majority for their power. Although there was a cabinet, it was appointed entirely by the monarch, and the monarch usually presided over its meetings.
The monarch could dismiss the minister at any time, or worse: Cromwell was executed and Clarendon driven into exile when they lost favour. Kings sometimes divided power equally between two or more ministers to prevent one minister from becoming too powerful. Late in Anne's reign, for example, the Tory ministers Harley and Viscount Bolingbroke shared power.
In the mid 17th century, after the English Civil War (1642–1651), Parliament strengthened its position relative to the monarch then gained more power through the Glorious Revolution of 1688 and passage of the Bill of Rights in 1689. The monarch could no longer establish any law or impose any tax without its permission and thus the House of Commons became a part of the government. It is at this point that a modern style of prime minister begins to emerge.
A tipping point in the evolution of the prime ministership came with the death of Anne in 1714 and the accession of George I to the throne. George spoke no English, spent much of his time at his home in Hanover, and had neither knowledge of, nor interest in, the details of British government. In these circumstances it was inevitable that the king's first minister would become the de facto head of the government.
From 1721, this was the Whig politician Robert Walpole, who held office for twenty-one years. Walpole chaired cabinet meetings, appointed all the other ministers, dispensed the royal patronage and packed the House of Commons with his supporters. Under Walpole, the doctrine of cabinet solidarity developed. Walpole required that no minister other than himself have private dealings with the king, and also that when the cabinet had agreed on a policy, all ministers must defend it in public, or resign. As a later prime minister, Lord Melbourne, said, "It matters not what we say, gentlemen, so long as we all say the same thing."
Walpole always denied that he was "prime minister", and throughout the 18th century parliamentarians and legal scholars continued to deny that any such position was known to the Constitution. George II and George III made strenuous efforts to reclaim the personal power of the monarch, but the increasing complexity and expense of government meant that a minister who could command the loyalty of the Commons was increasingly necessary. The long tenure of the wartime prime minister William Pitt the Younger (1783–1801), combined with the mental illness of George III, consolidated the power of the post. The title "prime minister" was first referred to on government documents during the administration of Benjamin Disraeli but did not appear in the formal British Order of precedence until 1905.