Question: Frans Luycx became the leading portrait painter to which Emperor?

Context articles: James Bowman (painter)
Godfrey Kneller
Ferdinand III, Holy Roman Emperor
Frans van Mieris the Elder
Sofonisba Anguissola
Bruce Corcoran
List of works by John Singer Sargent
Henry Raeburn
Gerard van Honthorst
Frans Luycx

James Bowman was an American itinerant artist and portrait painter.
 He was born in Allegheny County, Pennsylvania near Pittsburgh.
 Sometime between 1813 and 1815, James Bowman went to Chillicothe, Ohio, to learn to be a carpenter.
 There he met the itinerant painter Mr. J. T. Turner who taught him the rudiments of portrait painting (such as mixing paints).
 He gained considerable success when he started out professionally, painting in Pittsburgh and other communities in the early 1820s.
 He traveled to Philadelphia to learn from the masters there, but as a beginning artist could not make a living in that more cosmopolitan and competitive environment and became an itinerant portrait painter instead.
Sir Godfrey Kneller, 1st Baronet (born Gottfried Kniller; 8 August 1646 – 19 October 1723) was the leading portrait painter in England during the late 17th and early 18th centuries, and was court painter to English and British monarchs from Charles II to George I.
 His major works include "The Chinese Convert" (1687; Royal Collection, London); a series of four portraits of Isaac Newton painted at various junctures of the latter's life; a series of ten reigning European monarchs, including King Louis XIV of France; over 40 "Kit-cat portraits" of members of the Kit-Cat Club; and ten "beauties" of the court of William III, to match a similar series of ten beauties of the court of Charles II painted by his predecessor as court painter, Sir Peter Lely.
Ferdinand III (13 July 1608 – 2 April 1657) was Holy Roman Emperor from 15 February 1637 until his death, as well as King of Hungary and Croatia, King of Bohemia and Archduke of Austria.
 He was the last emperor to have real power over the Holy Roman Empire.
Frans van Mieris, the elder (16 April 1635 – 12 March 1681), was a Dutch Golden Age genre and portrait painter.
 The leading member of a Leiden family of painters, his sons Jan (1660–1690) and Willem (1662–1747) and his grandson Frans van Mieris the Younger (1689–1763) were also accomplished genre painters.
Sofonisba Anguissola (c. 1532  – 16 November 1625), also known as Sophonisba Angussola or Anguisciola, was an Italian Renaissance painter born in Cremona to a relatively poor noble family.
 She received a well-rounded education, that included the fine arts, and her apprenticeship with local painters set a precedent for women to be accepted as students of art.
 As a young woman, Anguissola traveled to Rome where she was introduced to Michelangelo, who immediately recognized her talent, and to Milan, where she painted the Duke of Alba.
 The Spanish queen Elizabeth of Valois was a keen amateur painter, and in 1559 Anguissola was recruited to go to Madrid as her tutor, with the rank of lady-in-waiting.
 She later became an official court painter to the king, Philip II, and adapted her style to the more formal requirements of official portraits for the Spanish court.
 After the queen's death, Philip helped arrange an aristocratic marriage for her.
 She moved to Sicily, and later Pisa and Genoa, where she continued to practice as a leading portrait painter, living to the age of ninety-three.
Bruce Corcoran , often known as Corky, is a recurring fictional character from the Jeeves novels of British comic writer P. G. Wodehouse, being a New York portrait painter turned cartoonist.
 In the 1990s television series "Jeeves and Wooster" he is portrayed by Greg Charles .
 Bruce Corcoran ("Corky"), a New York portrait painter turned cartoonist, asks Bertie to help him ask his wealthy uncle Alexander Worple to accept his girlfriend Muriel Singer so he can marry her.
 In order to get Worple's blessings and to attract the affection of Corky's wealthy uncle, Jeeves produces a plan which involves Corky's girlfriend Muriel Singer writing a book, which pleases Worple.
 At the end Jeeves writes "A Children’s Book of American Birds" in Muriel's place.
 Things go wrong and the uncle ends up Corky's dream marrying her.
 Alexander Worple marries Muriel Singer and Corky has only to paint a portrait of their baby.
 But Worple dislikes Corky's Abstract Expressionist portrait painting of the baby and cuts off Corky's allowance.
 Aunt Agatha comes with NY Chronicle Art Critic Arthur Prysock, an art critic with whom she wants to start and run her own art gallery.
 She is enamoured of the Abstract Expressionist portrait painting by Bruce Corcoran ("Corky"), and asks NY Chronicle Art Critic Arthur Prysock to buy it for her art gallery.
John Singer Sargent ( ; January 12, 1856 – April 14, 1925) was an American artist, considered the "leading portrait painter of his generation" for his evocations of Edwardian era luxury.
 During his career, he created roughly 900 oil paintings and more than 2,000 watercolors, as well as countless sketches and charcoal drawings.
 His "oeuvre" documents worldwide travel, from Venice to the Tyrol, Corfu, the Middle East, Montana, Maine, and Florida.
Sir Henry Raeburn {'1': ", '2': ", '3': ", '4': "} ( ; 4 March 1756 – 8 July 1823) was a Scottish portrait painter and Scotland's first significant portrait painter since the Union to remain based in Scotland.
 He served as Portrait Painter to King George IV in Scotland.
Gerard van Honthorst ("Gerrit van Honthorst") (4 November 1592 – 27 April 1656) was a Dutch Golden Age painter who became especially noted for his depiction of artificially lit scenes, eventually receiving the nickname Gherardo delle Notti ("Gerard of the nights").
 Early in his career he visited Rome, where he had great success painting in a style influenced by Caravaggio.
 Following his return to the Netherlands he became a leading portrait painter.
Frans Luycx or Frans Luyckx (before 17 April 1604 – 1 May 1668) was a Flemish painter who became the leading portrait painter at the imperial court of Emperor Ferdinand III in Vienna.
 He is best known for his portraits of the Emperor's family and various members of the Habsburgers, including its Austrian and Spanish branches.