Question: Virtù was a concept theorized by which Italian diplomat?

Context paragraphs:
Giulio Terzi di Sant'Agata: Giuliomaria Terzi di Sant'Agata (] (Count); born 9 June 1946) is an Italian diplomat who was Italy's Minister of Foreign Affairs from November 2011 until he resigned 26 March 2013.  From August 2008 to September 2009 he was the Permanent Representative of Italy to the United Nations in New York, where he also headed the Italian delegation to the United Nations Security Council, which Italy had joined as non-permanent member for the 2007–2008 term.  He then served as Italy's ambassador to the United States from 2009 to 2011.

Andreas Reinicke: Dr. Andreas Reinicke is a German diplomat and currently the German Ambassador to Tunisia.  He has been the European Union Special Representative for the Middle East Peace Process.  Alberto Oggero, an Italian diplomat, served as his deputy until 31 December 2013.  Dr Reinicke was appointed by the Council of the European Union on 23 January 2012, and his mandate was repealed on 1 January 2014, following proposals to the Political and Security Committee (PSC) by High Representative of EU for Common Foreign Affairs and Security Policy, Catherine Ashton.

Virtù: Virtù is a concept theorized by Niccolò Machiavelli, centered on the martial spirit and ability of a population or leader, but also encompassing a broader collection of traits necessary for maintenance of the state and "the achievement of great things."

Pietro Andrea Ziani: Pietro Andrea Ziani (1616 in Venice 1684 in Naples) was an Italian organist and composer.  He was the uncle of Marc'Antonio Ziani.  Beginning in 1669, he was the organist at St Mark's Basilica and later moved on to serve Eleonor Magdalene of Neuburg in Vienna.  His works included "L'Assalone punito" (1667) and the operas "La ricreazione burlesca" (1663), "L'invidia conculcata della virtù, merito, virtù, merito, valore di Leopoldo imperatore" (1664), "Cloridea" (1665), "Circe" (1665), "L'Elice" (1666) and "La Galatea" (1667).

Giuseppe Salvago Raggi: Giuseppe Salvago Raggi (17 May 1866 – 28 February 1946) was an Italian diplomat, born in Genoa.  He was ambassador of Italy to China (1899–1901) and France.  He was the Italian colonial governor of Somaliland (1906–1907) and Eritrea (1907–1915).

Sergio Vento: Sergio Vento (born May 30, 1938) is an Italian diplomat, former Permanent Representative of Italy to the United Nations and Italian Ambassador to the United States.

Niccolò Machiavelli: Niccolò di Bernardo dei Machiavelli (] ; 3 May 1469 – 21 June 1527) was an Italian diplomat, politician, historian, philosopher, humanist, and writer of the Renaissance period.  He has often been called the father of modern political science.  He was for many years a senior official in the Florentine Republic, with responsibilities in diplomatic and military affairs.  He also wrote comedies, carnival songs, and poetry.  His personal correspondence is renowned in the Italian language.  He was secretary to the Second Chancery of the Republic of Florence from 1498 to 1512, when the Medici were out of power.  He wrote his most renowned work "The Prince" ("Il Principe") in 1513.

Riccardo Di Lucchesi: Riccardo Astuto di Lucchese (January 1, 1882 – August 25, 1952) was an Italian diplomat and writer.  He was born in Naples.  He was Italian colonial governor of Eritrea.

Giacomo Durazzo: Count Giacomo Durazzo (27 April 1717 – 15 October 1794) was an Italian diplomat and man of theatre.  He was born into one of the most important aristocratic families in Genoa.  His brother was the famous doge Marcellino Durazzo.  In 1749, he became ambassador to the court in Vienna, where he was appointed director of the imperial theatres in the city in 1754.  He is most famous for working with the composer Christoph Willibald Gluck on reforming Italian opera.

Daniele Varè: Daniele Varè (1880-1956) was an Italian expatriate diplomat and author, most famous for the China-set novel "The Maker of Heavenly Trousers" (1935) which was republished in 2012 by Penguin Modern Classics.  He is also famous for the "Laughing Diplomat" (John Murray, 1938) his autobiography as Italian diplomat.

Supporting paragraphs: Virtù Niccolò Machiavelli
Answer: Niccolò di Bernardo dei Machiavelli