The Trissino family (pronounced Trìssino, ) is an ancient noble family from the Vicenza region. Of presumed Germanic origin,Giambattista Pagliarino, Croniche di Vicenza, 1663, book VI, pp. 250-252. the family received feudal investiture from both the Holy Roman Empire and the Church, being granted the title of count between the 10th and 11th centuries. Their domains included the eponymous town of Trissino, in the present-day Province of Vicenza, and nearby towns such as Valdagno, Cornedo Vicentino, Castelgomberto, and Sarego, so much so that the Valle dell'Agno was known for several centuries as the Valle di Trissino.Bernardo Morsolin, Giangiorgio Trissino o monografia di un letterato del secolo XVI, 1878, p. 2.

The Trissino family became influential around the year 1000 and throughout the struggles between the Guelphs and Ghibellines, constructing several castles in the Valle di Trissino.Antonio Canova, Giovanni Mantese, I castelli medioevali del vicentino, 1979, p. 239 and following. By the Renaissance period, they were considered one of the most prominent families in the city of Vicenza.Franco Barbieri, Mario Saccardo, Scamozzi a Vicenza-Palazzo Trissino Baston, 1996, p. 9.Silvano Fornasa, Trissino, famiglia, in AA.VV., Dizionario Biografico della Valle dell'Agno, 2012. From them emerged the collateral branch of the counts Trissino da Lodi, a distinguished family established between Milan and Piacenza, which developed a completely independent historical trajectory.

The most famous member of the dynasty was the humanist Gian Giorgio Trissino dal Vello d'Oro (1478–1550), renowned as the most illustrious intellectual from Vicenza in the 16th century and the mentor of Andrea Palladio.

A namesake and direct descendant, Gian Giorgio Trissino dal Vello d'Oro (1877–1963), was the first Italian to win at the Olympics, specifically at the 1900 Summer Olympics in Paris. On May 31, he placed second in the equestrian long jump, winning the first-ever Italian Olympic medal, and on June 2, he won first place in the equestrian high jump, earning Italy its first Olympic gold medal.

The family remains extant in Milan and the municipality of Gaiole in Chianti through the senior branch of the Trissino dal Vello d'Oro, whose youngest members represent the forty-fourth generation of the lineage, and between Vicenza and the town of Trissino through the cadet branch of the Trissino di Paninsacco.

History Origins The origins of the Trissino family are lost in the Early Middle Ages. Various historians and scholars between the 17th and 19th centuries outlined several possible hypotheses, based also on the interpretation of numerous documents preserved by the Trissino family themselves. Bernardo Morsolin, in his monograph on Gian Giorgio Trissino, mentions some of these, suggesting that the earliest Trissino may have belonged to the Drepsinates (the ancient inhabitants of the area) or arrived with the Cimbri during the barbarian invasions. However, in his subsequent essay Trissino ricordi storici of 1881,Bernardo Morsolin, Trissino ricordi storici, 1881, pp. 16 and following. he agrees with the claims of Giambattista Pagliarino, who stated that they descended from Germany around the 11th century ("with one or another of the Emperors of the House of Franconia"Bernardo Morsolin, Trissino ricordi storici, 1881, p. 35.) and built the ancient castle of Trissino, which later gave its name to the town and the entire valley. The historian Gaetano Maccà in his essayGaetano Maccà, Della Zecca Vicentina, 1802. regarding the existence of an ancient mint in Vicenza reconstructs the events of Nicolò Trissino, son of Paolo, who in 1013 was elected Governor of Vicenza and confirmed in office by Emperor Henry II with the authority to mint coins bearing the coat of arms of his family, a privilege later extended by Conrad II.Gaetano Maccà, Della Zecca Vicentina, 1802, pp. 19 and following, and later referenced in Francesco Schröder, Repertorio genealogico delle famiglie nobili venete, 1830, p. 330.

Traditional accounts, however, claim that the Trissino descend from a legendary hero, Achilles, son of Alcasto, who lived in the city of Troezen in the Peloponnese. At the age of eighteen, he reportedly followed the general Belisarius to Italy during the Gothic War. After the conflict, Achilles is said to have settled in the Valle di Trissino, which was named in memory of Troezen, thus laying the foundations of the family. Gian Giorgio Trissino included the exploits of these figures in his epic poem L'Italia liberata dai Goti of 1547, set during the Gothic War. In 1624, Paolo Beni reconstructed the family’s lineage in his Trattato dell'origine et fatti illustri della famiglia Trissina, in which he cited an ancient document tracing the family’s history, starting with Achilles.Paolo Beni, Trattato dell'origine et fatti illustri della famiglia Trissina, 1624, chapter III, pp. 16 and following. The theory of Greek origin is supported by Giovanni Pietro Romani in Corona della nobiltà d'Italia, who considers Paolo Beni’s narrative confirmed by the discovery of coins among the ruins of an ancient house in Castelvecchio di Valdagno, depicting figures in ancient Greek attire with the inscription of the Nobles of Troezen.Giovanni Pietro Romani, Corona della nobiltà d'Italia ovvero compendio dell'istorie delle famiglie illustri, 1639, pp. 584-586. The traditional lineage of the early Trissino is further detailed in an 18th-century manuscript by Parmenione Trissino, preserved in the so-called Trissino Archive – Trissino dal Vello d'Oro deposit of 1919 – at the Biblioteca Civica Bertoliana in Vicenza.

The most representative figures of the traditional lineage are:The complete list is published in Federico Bauce, La famiglia Trissino e la costruzione delle genealogie, in Claudio Povolo and Mattea Gazzola (eds.), Immagini di distinzione. Gli archivi della famiglia Trissino, 2012, pp. 72-73. Alcasto, likely born in 482 AD, married Ericinia, daughter of Timoteo, lord of Athens; Achilles (506–559), son of Alcasto, cupbearer to the Byzantine emperor Justinian I and captain in the war against the Goths, settled in the lands between the Agno and Chiampo rivers, married Carienta, daughter of Verulando, a subdued Goth, and had two sons: Giustino and Verulando; Giustino (545–608), son of Achilles, married the daughter of the lord of Castelgomberto, thus expanding his domains; Bonifacio, son of Ulieno, married Gisulfa, daughter of Gisulf II, Duke of Friuli; Alessandro, son of Alcasto, captain of the ships of Maritime Venice during its revolts against the Exarchate and the Lombards (7th century), married Alessia, daughter of Orso (d. 737), third Doge of Venice; Giorgio, son of Alessandro, the first with this name, lived 103 years; Antonio, son of Claudio, whose possessions in Chiampo and Arzignano were devastated by the Hungarians (9th century); Corrado, son of Antonio, fought for Henry, Duke of Bavaria, brother of Emperor Otto the Great (10th century); Nicolò, son of Paolo, appointed imperial vicar, minted coins at the city mint in the 11th century, as cited by Gaetano Maccà in his work Della Zecca Vicentina, 1802; Eugenio, son of Nicolò, lived 48 years. Exiled from Vicenza in 1054, he may be the possible progenitor of the Trissino da Lodi family. Enrico, son of Olderico, "served under Rodolfo, son of Emperor Henry"; Olderico II, son of Teobaldo, hosted Frederick Barbarossa on November 3, 1154, who confirmed the lordship over the lands of the Valle dell'Agno and the title of count; Olderico III, son of Uguccione, the first figure with recognized primary documentary evidence.

Middle Ages The first family member with historical evidence from primary sourcesRosa Maria Gregoletto, Una famiglia signorile vicentina nei secoli XIII e XIV: i Trissino, in Gherardo Ortalli and Michael Knapton (eds.), Istituzioni, società e potere nella marca trevigiana e veronese (secoli XIII e XIV), 1988, pp. 179-197. was Olderico (Olderico III according to the family historiography compiled by Parmenione Trissino), son of Uguccione.Franco Barbieri, Mario Saccardo, Scamozzi a Vicenza-Palazzo Trissino Baston, 1996, p. 9 and related notes. It is documented that Olderico was among the Vicentine nobles who received the oath of allegiance from the Commune of Bassano in 1175.Bernardo Morsolin, Trissino ricordi storici, 1881, p. 135.Rosa Maria Gregoletto, I Trissino cit., p. 181. According to a study analyzing the rapid economic growth in the second half of the 12th century driven by the Trissino family, it is hypothesized that Olderico may have been the founder of the village that is now the city of Valdagno.Giorgio Cracco, Valdagno: alle origini di una storia e di un nome, in Storia della Valle dell'Agno. L'ambiente, gli uomini, l'economia, ed. G. A. Cisotto, 2001.

Based on the oldest documents available today, it appears that around the year 1000, power in the Valle dell'Agno was managed solely by ecclesiastical entities, such as the Vicentine diocesan chancery and the Veronese monasteries of San Zeno and Santa Maria in Organo.Silvano Fornasa, Territorio, economia e società nella Valle dell’Agno del XIII secolo, 2010, pp. 5-6. The Trissino family’s skill likely lay in their ability to navigate between major powers (Empire and Church) to increase their influence. By the 11th century, it is plausible that they were part of the Vicentine curia vassallorum. The earliest recorded episcopal investiture received by the Trissino family dates to 1219, referencing an earlier one, likely granted by Bishop Pistore to Olderico in the second half of the 12th century.Silvano Fornasa, L'età medioevale, in Giorgio Trivelli (ed.), Storia di Trissino, 2003, p. 66.Federico Bauce, La famiglia Trissino e la costruzione delle genealogie, cit., p. 58. Feudal investitures included extensive rights and jurisdictions, such as tax collection, justice administration, appointment of deans, and grazing rights. The fact that Grifolino, son of Olderico, is mentioned in the 1208 Building Decree, cited by Giovanni da Schio, as the owner of the turris domus grandis near the Vicenza Cathedral (the same area where Palazzo Trissino al Duomo was built three centuries later), may further testify to the close, even political, ties between the Trissino family and the diocesan chancery.

Olderico married Chiara of San Bonifacio from Verona,Federico Bauce, La famiglia Trissino e la costruzione delle genealogie, cit., note 5 at p. 59. a member of one of the city’s leading families,Andrea Castagnetti, Le due famiglie comitali veronesi: i San Bonifacio e i Gandolfingi-di Palazzo, in Studi sul Medioevo veneto, 1981. evidence of the strong relationships forged by the Trissino family with representatives of imperial powers (at that time, Verona was the capital of the March of Verona, a subdivision of the Holy Roman Empire encompassing the Triveneto region). From Chiara, Olderico had eight children, four of whom are considered progenitors or colonelsOn the origin of the term colonel to designate family branches, see Sante Bortolami, Colmellum, Colonellum, in Gherardo Ortalli and Michael Knapton (eds.), Istituzioni, società e potere nella marca trevigiana e veronese (secoli XIII e XIV), 1988, pp. 221-234. of their respective branches: Miglioranza (Miglioranza branch); Paninsacco (Paninsacco branch); Arnoaldo (Dalla Pietra branch); Corrado (Castelmaggiore branch). The latter two participated only marginally in Vicenza’s political life: the Castelmaggiore branch became extinct with Corrado’s four children (13th century),Rosa Maria Gregoletto, I Trissino cit., table 5 at p. 192. while the Dalla Pietra branch is known only until the 15th century (with Bugamante, Giacomo, and Pierantonio, sons of Antonio di Giacomo).Rosa Maria Gregoletto, I Trissino cit., table 4 at p. 191.