Question: HMS Dartmouth was wrecked while on a mission to persuade the MacLeans of Duart to sign allegiance to a male monarch, informally known by what name in Northern Ireland and Scotland?

Context paragraphs:
Northern Ireland national under-16 football team: The Northern Ireland national under-16 schools football team (also known as Northern Ireland schoolboys, under-16s or U16) represents Northern Ireland in association football at under-16 level.  It is controlled by the Northern Ireland Schools Football Association (NISFA) which is affiliated to the Irish Football Association.  The main competition competed for by the team is the Victory Shield which has been competed for since 1925 by the same four teams (England, Northern Ireland, Scotland and Wales).  The Northern Ireland under-16 side also competes regularly in other minor tournaments and in friendlies.  The team had previously been fielded at under-15 level and games are still sometimes arranged at this age group level with the agreement of the opposition association.

Vanguard Unionist Progressive Party: The Vanguard Unionist Progressive Party (VUPP), informally known as Ulster Vanguard, was a unionist political party which existed in Northern Ireland between 1972 and 1978.  Led by William Craig, the party emerged from a split in the Ulster Unionist Party (UUP) and was closely affiliated with several loyalist paramilitary groups.  The presence of features such as an honour guard and a common salute led opponents to accuse it of being fascist.  The party was set up in opposition to power sharing with Irish nationalist parties.  It opposed the Sunningdale Agreement and was involved in extra-parliamentary activity against the agreement.  However, in 1975, during discussions on the constitutional status of Northern Ireland in the constitutional convention, William Craig suggested the possibility of voluntary power sharing with the nationalist Social Democratic and Labour Party.  In consequence the party split, with dissenters forming the United Ulster Unionist Party.  Thereafter Vanguard declined and following poor results in the 1977 local government elections, Craig merged the remainder of Vanguard into the UUP in February 1978.

Irish Sign Language: Irish Sign Language (ISL, Irish: "Teanga Chomharthaíochta na hÉireann" ) is the sign language of Ireland, used primarily in the Republic of Ireland.  It is also used in Northern Ireland, though British Sign Language (BSL) is also used there.  Irish Sign Language is more closely related to French Sign Language (LSF) than to British Sign Language, though it has influence from both languages.  It has influenced sign languages in Australia and South Africa, and has little relation to either spoken Irish or English.

William III of England: William III (Dutch: "Willem" ; 4 November 1650 – 8 March 1702), also widely known as William of Orange, was sovereign Prince of Orange from birth, Stadtholder of Holland, Zeeland, Utrecht, Gelderland, and Overijssel in the Dutch Republic from 1672, and King of England, Ireland, and Scotland from 1689 until his death.  It is a coincidence that his regnal number (III) was the same for both Orange and England.  As King of Scotland, he is known as William II.  He is sometimes informally known in Northern Ireland and Scotland as "King Billy".

HMS Dartmouth (1655): HMS "Dartmouth" was a small frigate or fifth-rate ship, one of six ordered by the Council of State on 28 December 1654 and built in 1655.  At the end of July 1689 HMS Dartmouth, commanded by John Leake, managed to break through the boom on the River Foyle allowing the siege of Londonderry by forces of James II to be relieved.  After a lengthy career in the Royal Navy, she was wrecked in the Sound of Mull on 9 October 1690, while on a mission to persuade the MacLeans of Duart to sign Articles of Allegiance to William III and Mary II.

Match of the Day from Northern Ireland: Match of the Day from Northern Ireland is the name given to coverage of football matches involving local teams in Northern Ireland and the Northern Ireland national football team, produced and broadcast by BBC Northern Ireland.  It is shown on either BBC One Northern Ireland or BBC Two Northern Ireland depending on the match and availability in the schedule, while some of Northern Ireland's international matches have also been broadcast throughout the United Kingdom via the BBC Red Button interactive channels on Freeview and Sky Digital.

Secretary of State for Northern Ireland: Her Majesty's Principal Secretary of State for Northern Ireland, informally known as the Northern Ireland Secretary (Irish: "Rúnaí Stáit Thuaisceart Éireann" ), is the principal secretary of state in Her Majesty's Government with responsibilities for Northern Ireland.  The Secretary of State is a Minister of the Crown who is accountable to the Parliament of the United Kingdom and is the chief minister in the Northern Ireland Office.  As with other ministers, the position is appointed by the British monarch on the advice of the Prime Minister.

Health and Social Care in Northern Ireland: Health and Social Care in Northern Ireland (HSC) is the designation of the publicly funded service which provides public health and other social care services in Northern Ireland.  The Northern Ireland Executive through its Department of Health is responsible for its funding, while the Public Health Agency is the executive agency responsible for the provision of health and social care services across Northern Ireland.  It is free of charge to all citizens of Northern Ireland and the rest of the United Kingdom.  For services such as A&E, patients simply walk in, state their name and date of birth, are given treatment and then leave.  Patients are unaware of costs incurred by them using the service.  It is sometimes called the "NHS", as in England, Scotland and Wales, but differs from the NHS in England and Wales in that it provides not only health care but social care too (the NHS in Scotland also includes social care).  Social services are provided by local councils.  The Health and Social Care service was created by the Parliament of Northern Ireland in 1948 after the Beveridge Report.

HM Prison: Her Majesty's Prisons (His Majesty's Prisons in the case of a male monarch) is the name given to prisons in the United Kingdom, as well as some in Australia and a small number in Canada, Grenada, and Barbados.  The title makes up part of the name of individual prisons and is usually abbreviated to HM Prison or HMP.

Languages of Northern Ireland: English is the most spoken language in Northern Ireland.  There are also two recognised regional languages in Northern Ireland: the Irish language ("see Irish language in Northern Ireland") and the local variety of Scots known as Ulster Scots.  Northern Ireland Sign Language and Irish Sign Language have been recognised since 29 March 2004.

Supporting paragraphs: HMS Dartmouth (1655) William III of England
Answer: "King Billy"