The most significant Hungarian painter of his age. Mányoki, the son of a protestant priest, learnt to paint in Hamburg first, then he became a pupil of A. Scheitz, a famous German painter, in Hannover. His development was especially influenced by French portrait painters, in particular by Largilliere. He served the Prussian court where he met the wife of Ferenc Rákóczi II, a reigning prince, then the prince himself, who soon made him his court painter. He was sent on a diplomatic mission to the Netherlands. On Rákóczi's recommendation, he was taken into the service of Augustine, the Strong, Saxonian prince-elector and Polish king. He worked in Warsaw in 1713, in Dresden and in Berlin in 1714 where he painted mostly portraits of people and famous beauties of the court.

He returned to Hungary in 1724 to settle down. Although he had orders from aristocratic families to paint portraits, he did not earn enough to live on painting. From 1732 he worked in Berlin and Leipzig, and then in Dresden until his death.

He was a great talent of Baroque portrait painters. His major works: "Self-Portrait", "Portraits of Ferenc Rákóczi II" in Hungary (1708) and Danzig (1712), "The Portrait of Mrs Bercsényi" (1712), "The Duke of Flemming" (1713) and "An Unknown Hungarian Aristocrat", portraits of the prince of Anhalt's family and mistresses ("The Duchess of Montmororency", 1714, "The Countess of Cosel", 1715, and "The Countess of Dörrhoff", 1713, 1716). In the Hapsburg court, he painted portraits of Karl VI, the child Marie Therese and Marie Anne (1723). His visits to Hungary produced the portraits of the Ráday, Podmaneczky, etc. families, complying with the provincial style in portrait painting. Significant works of his last perio "Rechberg, Professor of Law", "Blendinger, Goldsmith", "W.G. Knebelsdorff" (1732), "The Sulkowski Children" (1734), "A Boy in Fancy Dress" and "A Girl". The most mature and individual picture of this periods is "The Portrait of A. Thiele, Painter" (1737),