Duchy of Lancaster in the context of "Sheriff of Cornwall"

There have been 13 British monarchs since the political union of the Kingdom of England and the Kingdom of Scotland on 1 May 1707. The first British monarch was Anne, who reigned between 1707 and 1714; the current monarch is Charles III since his accession in September 2022. Although the informal style of "King of Great Britain" had been in use since the personal union of England and Scotland on 24 March 1603 under James VI and I, the official title came into effect legislatively in 1707 and therefore British monarchs do not include monarchs who held both the title of Monarch of England and Monarch of Scotland at the same time.

On 1 January 1801, the Kingdom of Great Britain and the Kingdom of Ireland merged to create the United Kingdom of Great Britain and Ireland. This later became the United Kingdom of Great Britain and Northern Ireland upon the secession of the Irish Free State (now the Republic of Ireland) in the 1920s. British monarchs have also held various other titles reflecting their claims outside of the United Kingdom, including Elector of Hanover, Emperor of India, and Head of the Commonwealth; they also hold various secondary titles for land within the United Kingdom, such as the Duchy of Lancaster.

The Sovereign Grant Act 2011 (c. 15) is the act of the Parliament of the United Kingdom that introduced the Sovereign Grant, the payment that is paid annually to the monarch by the government in order to fund the monarch's official duties. It is usually set as a percentage of annual income from the Crown Estate. The Sovereign Grant Act 2011 was the biggest reform to the finances of the British royal family since the inception of the Civil List in 1760. In addition to the Sovereign Grant, the monarch continues to receive the revenue of the Duchy of Lancaster, while the Prince of Wales receives the revenues of the Duchy of Cornwall.

The Chancellor of the Duchy of Lancaster is a ministerial office in the Government of the United Kingdom. Excluding the prime minister, the chancellor is the highest ranking minister in the Cabinet Office, immediately after the prime minister, and senior to the Minister for the Cabinet Office. The Chancellor of the Duchy of Lancaster is the most senior minister within the Cabinet Office, but the role does not outrank other Cabinet ministers and does not have automatic authority outside that department. The role includes as part of its duties the administration of the estates and rents of the Duchy of Lancaster.

Formally, the chancellor of the Duchy of Lancaster is appointed by the Sovereign on the advice of the prime minister, and is answerable to Parliament for the governance of the Duchy. In modern times, however, the involvement of the chancellor in the running of the day-to-day affairs of the Duchy is slight, and the office is held by a senior politician whose main role is usually quite different. In practical terms, it is a sinecure, allowing the prime minister to appoint an additional minister without portfolio to the Cabinet of the United Kingdom. The corresponding shadow minister is the shadow chancellor of the Duchy of Lancaster.

The dukedom of Lancaster is a former English peerage, created three times in the Middle Ages, which finally merged in the Crown when Henry V succeeded to the throne in 1413. Despite the extinction of the dukedom the title has continued to be used to refer to the reigning monarch of the United Kingdom in relation to the County Palatine of Lancaster and the Duchy of Lancaster, an estate held separately from the Crown Estate for the benefit of the sovereign.