Question: The Foscari reached its peak with Francesco Foscari, who reached what chief magistrate of Venice?

Context paragraphs:
Ca' Foscari University of Venice: Ca' Foscari University of Venice (Italian: "Università Ca' Foscari Venezia" ) is a public university in Venice, Italy; it is usually known simply as Università Ca' Foscari.  Since its foundation in 1868 it has been housed in the Venetian Gothic palace of Ca' Foscari, from which it takes its name.  The palace stands on the Grand Canal, between the Rialto and San Marco, in the sestiere of Dorsoduro.

Marina Nani: Marina Nani (d. after 1457) was a Dogaressa of Venice by marriage to the Doge Francesco Foscari (r. 1423-1457).

I due Foscari: I due Foscari ("The Two Foscari") is an opera in three acts by Giuseppe Verdi to an Italian libretto by Francesco Maria Piave, based on a historical play, "The Two Foscari" by Lord Byron.

Foscari: The Foscari were an ancient Venetian patrician family, which reached its peak in the 14th–15th centuries, culminating in the dogeship of Francesco Foscari (1423–1457).

The Two Foscari (Byron): The Two Foscari: An Historical Tragedy (1821) is a verse play in five acts by Lord Byron.  The plot, set in Venice in the mid 15th century, is loosely based on the true story of the downfall of doge Francesco Foscari and his son Jacopo.  Byron's play formed the basis of Verdi's opera "I due Foscari".

Pasquale Malipiero: Pasquale Malipiero, called the "dux pacificus" (born Venice, 1392 – died there May 7, 1462) was a Venetian statesman who served as the 66th Doge of Venice from October 30, 1457 until his death.  He succeeded Francesco Foscari, and was specifically elected by enemies of the Foscari family.  In 1458, he signed into law a number of measures limiting the power of the Council of Ten.  He was interred in the Basilica di San Giovanni e Paolo, a traditional burial place of the doges.  He was succeeded as Doge by Cristoforo Moro.  He was married to Giovanna Dandolo.

Francesco Foscari: Francesco Foscari (19 June 1373 – 1 November 1457) was the 65th Doge of the Republic of Venice from 1423 to 1457.  His reign, the longest of all Doges in Venetian history, lasted 34 years, 6 months and 8 days, and coincided with the inception of the Italian Renaissance.

Pietro Loredan: Pietro Loredan (1372 – 28 October 1438) was a Venetian nobleman and distinguished military commander both on sea and on land.  He fought against the Ottomans, winning the Battle of Gallipoli (1416), played a leading role in the conquest of Dalmatia in 1411–1420, and participated in several campaigns against Venice's Italian rivals, Genoa and Milan, to secure Venice's mainland domains (Terraferma).  He also held a number of senior political positions as "Avogador de Comùn", ducal councillor, and governor of Zara, Friuli, and Brescia, and was honoured with the position of Procurator of St Mark's in 1425.  In 1423, he contended for the position of Doge of Venice, but lost to his bitter rival Francesco Foscari; their rivalry was such that when Loredan died, Foscari was suspected of having poisoned him.

Achille De Bassini: Achille De Bassini (5 May 1819 – 3 July 1881) was an Italian baritone, particularly noted for his performances in Verdi's operas.  He created the roles of Francesco Foscari in "I due Foscari" (1844), Pasha Seid in "Il corsaro" (1848), Miller in "Luisa Miller" (1849) and Fra Melitone in "La forza del destino' (1862).

Doge of Venice: The Doge of Venice ( ; Venetian: "Doxe de Venexia" ] ; Italian: "Doge di Venezia" ] ; all derived from Latin "dūx ", "military leader"), sometimes translated as Duke (compare the Italian "Duca "), was the chief magistrate and leader of the Most Serene Republic of Venice for 1,100 years (697-1797).

Supporting paragraphs: Foscari Doge of Venice
Answer: Doge of Venice