Baron Philipp von Neumann (; ; 4 December 1781 – 14 January 1851) was an Austrian diplomat. Birth and family Neumann was born in Brussels (then in the Austrian Netherlands), the son of Carl von Neumann (an official in the Habsburg administration) and his wife, Marie Ducpetiaux. Nothing is known of his education, but, since he did not begin work until he was 21, it seems likely that he attended university. His brother was General-major Maximillian Ritter von Neumann (c. 1778–1846). Diplomatic career Neumann began his career in the Austrian Treasury Service in 1802 and was posted to Venice which had come under Austrian control a few years previously. After just over a year he joined the diplomatic service and was posted to Paris where Prince Klemens Wenzel von Metternich was Austrian ambassador. Later Neumann joined the staff of the Austrian embassy in London under the ambassador Prince Esterházy; Neumann served as chargé d'affaires in his absence. Neumann's activity was regarded as notable, especially in 1814 and 1815, on the occasion of the remittance of the British subsidies to the Austrian government, when he succeeded in obtaining very favourable conditions for Austria on the question of the rate of exchange. He was on excellent terms with the Duke of Wellington, whose grandniece he married, and with Castlereagh. When Wellington repeated his famous remark that "Nothing except a battle lost can be half as melancholy as a battle won", Neumann tactfully replied that in fact Wellington had never lost a battle. He described Castlereagh's suicide as "a great mystery which perhaps time will explain". In 1824 Neumann took part in the negotiations between Portugal and Brazil, as a result of King John VI of Portugal and his son Emperor Pedro I of Brazil were reconciled. In December 1826 Neumann was sent to Brazil to negotiate the marriage of Pedro's daughter Maria to his brother Miguel, and the demand by Miguel that he be recognised as regent of Portugal. In October of the following year he attended the negotiations on this matter carried on at Vienna. In December 1829 Neumann conducted the Treaty of Commerce between Austria and Great Britain. In recognition of his services he was created a Baron by the Emperor Francis I of Austria on 31 August 1830. In 1844 Neumann became Minister Plenipotentiary and Envoy Extraordinary for Austria to the Court of St. James's. In 1845 he was