Question: Who commissioned the documentary about the investiture of the Duke of Cornwall?

Context paragraphs:
Surfing Tommies: Surfing Tommies is a 2009 play by the Cornish author Alan M. Kent.  It follows the lives of three members of the Duke of Cornwall's Light Infantry on a journey from the mines of Cornwall to the fields of Flanders, where they learn to surf from South African troops.  It has been adapted as a radio play and was toured round Cornwall by Bish Bash Bosh Productions in 2009 and nationally in 2011.

Duke of Rothesay: 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.

Charles, Prince of Wales: 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.

Duchy of Cornwall: The Duchy of Cornwall (Cornish: Duketh Kernow ) is one of two royal duchies in England, the other being the Duchy of Lancaster.  The eldest son of the reigning British monarch inherits possession of the duchy and title of Duke of Cornwall at birth or when his parent succeeds to the throne, but may not sell assets for personal benefit and has limited rights and income as a minor.  If the monarch has no male children, the rights and responsibilities of the duchy belong to The Crown and there is no duke.  The current duke is Charles, Prince of Wales.

Honours of the Principality of Wales: The Honours of the Principality of Wales are the regalia used at the investiture of Princes of Wales, made up of a coronet, a ring, a rod, a sword, a girdle, and a mantle.  All but the coronet date from the investiture of Prince Edward (later Edward VIII then Duke of Windsor) in 1911 when most of the Honours of Wales were redesigned.

Royal Family (documentary): Royal Family is a documentary about the family of Queen Elizabeth II, and was aired on 21 June 1969.  It was rebroadcast on ITV the following week.  The film was commissioned by the Queen to celebrate the investiture of her eldest son, Charles, as Prince of Wales.  The script was written by Antony Jay.

Duchess of Cornwall: The Duchess of Cornwall is the title held by the wife of the Duke of Cornwall.  Duke of Cornwall is a non-hereditary peerage held by the British Sovereign's eldest son and heir.

Cornwall Hill: Cornwall Hill is a small township south of Pretoria, Gauteng, South Africa, It borders the township of Irene.  Cornwall Hill takes its name from the Duke of Cornwall's Light Infantry brigade that was stationed here during the Anglo-Boer war.

Cornish National Library: The Cornish National Library, National Library of Cornwall, or Cornish National Archive, is a proposed facility for the exhibition, research and storage of Cornwall's documentary and manuscript archives, currently held at Cornwall Record Office, the Cornish Studies Centre and various other collections, libraries and institutions both within Cornwall and outside.

Killigrew baronets: The Killigrew Baronetcy, of "Arwennick" in the County of Cornwall, was a title in the Baronetage of England.  It was created on 22 December 1660 for William Killigrew (d.1665), 6th son of John Killigrew (c.1557-1605) of Arwenack, near Falmouth in Cornwall, thrice MP for Penryn in 1584, 1586 and 1597, and Vice-Admiral of Cornwall and like his father and grandfather was Captain of Pendennis Castle (1584-98) The 1st Baronet was created a baronet at the Restoration of the Monarchy in 1660, which event was largely brought about by his uncle George Monck, 1st Duke of Albemarle (1608-1670).  He died without progeny and the title by special remainder descended to his nephew Peter Killigrew, son of his elder brother Sir Peter Killigrew (1593-1667), MP for Camelford.  The second Baronet was Member of Parliament for Camelford.  The title became extinct on his death in 1704.

Supporting paragraphs: Royal Family (documentary) Charles, Prince of Wales
Answer: the Queen