Heinrich Thyssen had abandoned Germany as a young man and, after studying chemistry at the University of Heidelberg and philosophy at the University of London and obtaining a doctorate, he settled in Hungary in 1905 and married Baroness Margit Bornemisza de Kászon et Impérfalva (Csetény, Veszprém, 23 July 1887 – Locarno, 17 April 1971) in Vienna or Budapest on 4 January 1906 and became a citizen of Austria-Hungary.
His mother-in-law was English American Mathilde Louise Price (Wilmington, New Castle County, Delaware, 14 March 1865 – Locarno, 19 January 1959 and married at Vienna on 16 May 1883), who was a sister of Anne Hollingsworth Price (wife of Friedrich Wilhelm, Prince of Ardeck) and they were descendants of the Winthrop family, and related to Daniel M. Frost and John Kerry.
[1] The couple lived at the castle of Rohonc until after World War I and the uprising of Béla Kun, when they fled and moved to The Hague in the Netherlands from whence they directed some of the Thyssen commercial and industrial interests, including the Bank voor Handel en Scheepvaart.
In 1926 he had refused to participate in the Vereinigte Stahlwerke AG, founded by his elder brother Fritz Thyssen, although becoming a board member, but kept his own inherited wealth, including his father's foreign investments and some German companies apart from the Thyssen steelworks, in a separate organization, the August Thyssensche Unternehmungen des In- und Auslandes, GmbH, today Thyssen-Bornemisza Group Holdings N.V. (TBG).
Among other works, he bought from the estate of the American banker Otto Hermann Kahn, Maecenas of the Metropolitan Opera House of New York, in 1935, the painting Portrait of a Knight by Vittore Carpaccio, which currently remains in the collection.