The Crown Prince of Thailand (or Siam; Thai: สยามมกุฎราชกุมาร ; rtgs: Sayammakutratchakuman ) is a title held by the heir apparent to the Thai throne.
 First created by King Chulalongkorn (Rama V) in 1886, for his son Prince Maha Vajirunhis, the king's eldest son by a royal wife Queen Savang Vadhana.
 Prior to this, the Siamese throne did not have a law or formal system regulating the royal succession.
 In 1688 King Petracha of Ayutthaya created the title of Front Palace, which by the Rattanakosin period had become the main title granted to the heir presumptive to the throne.
 However few Front Palaces have succeeded to the throne this way, with the exception of King Buddha Loetla Nabhalai (Rama II) in 1809.
 After the Front Palace crisis in 1875, the title of Front Palace was abolished and replaced with the title of Crown Prince, who became heir apparent to the throne.
Prince of Beira (Portuguese: "Príncipe da Beira" ) is a title traditionally granted to the heir apparent of the heir apparent to the throne of Portugal.
 The title's original use that it be granted on the eldest daughter of the reigning monarch of Portugal.
 Tied with the title of Prince of Beira, is Duke of Barcelos, as heir to the Duke of Braganza and Prince of Brazil ("later" Prince Royal of Portugal).
 The current Prince of Beira is Prince Afonso, the eldest son of Duarte Pio, Duke of Braganza.
Penlop of Trongsa (Dzongkha: ཀྲོང་གསར་དཔོན་སློབ་; Wylie: "Krong-gsar dpon-slob"), also called Chhoetse Penlop (Dzongkha: ཆོས་རྩེ་དཔོན་སློབ་; Wylie: "Chos-rtse dpon-slob"; also spelled "Chötse"), is a Dzongkha title meaning "Governor of the Province of Trongsa (Chhoetse)".
 It is generally given to the heir apparent of the Kingdom of Bhutan.
 The most recent holder of the title was King Jigme Khesar Namgyel Wangchuck, who was then a prince (Dzongkha: "dasho", "gyalsey").
 Although the current heir presumptive is Prince Jigyel Ugyen Wangchuck, the title is reserved for the officially designated heir apparent, which is subject to change by the reigning king.
 Also, the reigning Druk Gyalpo may retain the office or award it to another person after coronation.
 The proper reference style is His Royal Highness Trongsa (Chhoetse) Penlop.
The monarch of Belize is the head of state of Belize.
 The incumbent is Queen Elizabeth II, officially called Queen of Belize, who has reigned since 21 September 1981.
 The heir apparent is Elizabeth's eldest son, Prince Charles, though the Queen is the only member of the royal family with any constitutional role.
 She, her husband and consort, Prince Philip, Duke of Edinburgh, Prince Charles, and other members of the royal family, including the Queen's other children and cousins, undertake various public ceremonial functions across Belize and on behalf of Belize abroad.
Charles, Prince of Wales (Charles Philip Arthur George; born 14 November 1948) is the eldest child and heir apparent of Queen Elizabeth II.
 Known alternatively in Cornwall as Duke of Cornwall and in Scotland as Duke of Rothesay, he is the longest-serving heir apparent in British history, having held the position since 1952.
 He is also the oldest person to be next in line to the throne since Sophia of Hanover (the heir presumptive to Queen Anne), who died in 1714 at the age of 83.
Prince Franz Wilhelm of Prussia ("Franz Wilhelm Victor Christoph Stephan"; born 3 September 1943) is a German businessman and member of the House of Hohenzollern, the former ruling German imperial house and royal house of Prussia.
 From 1976 to 1986 he was known as Grand Duke Mikhail Pavlovich of Russia.
 As a descendant of Wilhelm II, he is also a great-great-great-grandson of Queen Victoria and a fourth cousin of Charles, Prince of Wales.
Duke of Rothesay (Scottish Gaelic: "Diùc Baile Bhòid" , Scots: "Duik o Rothesay" ) is a dynastic title of the heir apparent to the British throne, currently Prince Charles.
 It was a title of the heir apparent to the throne of the Kingdom of Scotland before 1707, of the Kingdom of Great Britain from 1707 to 1801, and now of the United Kingdom of Great Britain and Northern Ireland.
 It is the title mandated for use by the heir apparent when in Scotland, in preference to the titles "Duke of Cornwall" (which also belongs to the eldest living son of the monarch, when and only when he is also heir apparent, by right) and "Prince of Wales" (traditionally granted to the heir apparent), which are used in the rest of the United Kingdom and overseas.
 The Duke of Rothesay also holds other Scottish titles, including those of Earl of Carrick, Baron of Renfrew, Lord of the Isles and Prince and Great Steward of Scotland.
 The title is named after Rothesay on the Isle of Bute, Argyll and Bute, but is not associated with any legal entity or landed property, unlike the Duchy of Cornwall.
On 6 February 2017, the Sapphire Jubilee of Queen Elizabeth II, marking sixty-five years of her reign, occurred.
 The longest-reigning monarch in British history, Queen Elizabeth II was the first British monarch to have a sapphire jubilee.
 This Jubilee featured blue stamps from the Royal Mail, commemorative coins from the Royal Mint, and a reissue of an official 2014 portrait of Queen Elizabeth II by David Bailey.
 In this official portrait the Queen wears sapphire jewellery which she received as a wedding present from her father.
 The Jubilee also involved a gun salute at the Tower of London, a gun salute in Green Park, gun salutes in several other places around the United Kingdom, and the ringing of the bells in Westminster Abbey.
 Theresa May, the Prime Minister of the United Kingdom, congratulated Queen Elizabeth II in regard to the occasion, saying in part, "I know the nation will join with me today in celebrating and giving thanks for the lifetime of service Her Majesty the Queen has given to our country and to the Commonwealth."
This is a list of those people who were heir apparent or heir presumptive to the Kingdom of Prussia from its foundation in 1701 to the end of the monarchy in 1918.
 From 18 January 1871 the Crown Prince of Prussia was also heir apparent to the German Empire.
 Those heirs who succeeded are shown in bold.
The monarchy of Canada is at the core of both Canada's federal structure and Westminster-style of parliamentary and constitutional democracy.
 The monarchy is the foundation of the executive (Queen-in-Council), legislative (Queen-in-Parliament), and judicial (Queen-on-the-Bench) within both the federal and each provincial jurisdiction.
 The sovereign is the personification of the Canadian state and "is" Canada as a matter of constitutional law.
 The current Canadian monarch is Queen Elizabeth II, who has reigned since 6 February 1952.
 Royal succession is determined according to common and statute law, which stipulates the throne is inherited by the sovereign's eldest living, non-Catholic child or, in the case of a childless sovereign, the nearest collateral line.
 As such, Elizabeth's son, Prince Charles, is heir apparent.

Question: Who is the fourth cousin of Prince Franz Wilhelm of Prussia and the current heir apparent of Queen Elizabeth II?
Answer: Charles, Prince of Wales