CESI. - A family of Umbrian-Sabine origin from the town of the same name, which began to rise in the 15th century and during the 16th century one of its branches united the marquisate of Monticelli (1572), the duchy of Acquasparta (1588), and the principality of S. Angelo and S. Paolo (1613). Its fortunes in the Roman Curia began with Paolo Emilio, b. in 1481, apostolic protonotary, created cardinal by Leo X in the great promotion of 1 Apr. 1517. With him begins that series of figures who held cardinalates and bishoprics during the 16th century and the beginning of the following one. Indeed, Paolo Emilio was granted in commendam Todi on 1 June 1523, Narni on 20 May 1525 (which he transferred to Bartolomeo C. a few months later), Orte on 7 Apr. 1525 (transferred to Pomponio C. in 1538), Cervia in 1525 (transferred to Ottavio C. in 1528), and even Sion in Switzerland, which he held from 12 Nov. 1522 until his death, which overtook him at the age of 56 in the Curia on 5 Aug. 1537. He was also archpriest of S. Maria Maggiore. Upon the death of Card. Giov. Antonio di S. Giorgio (1511), he acquired his palace in Borgo Vecchio and completed it by turning the vineyard extending over the hill behind into a garden and creating an antiquarium of important antiquities gathered from the discoveries being made everywhere at that time (cf. An. Hülsen, Römische Antihengärten des XVI. Jahrh., Heidelberg 1917; E. Martinori, op. cit. in bibl., p. 47 ff.).
Federico, brother of Paolo Emilio, b. in 1500, was granted the bishopric of Todi by renunciation of his brother on 11 June 1523 and held it until 1545; he was created cardinal by Paul III on 19 Dec. 1544; he held Cremona in commendam from 18 Mar. 1551 to 13 Mar. 1560; he died bishop of Porto on 28 Jan. 1565 and was buried at S. Maria Maggiore. He was considered wealthy, learned, and of great experience; he built in Rome the church of S. Caterina dei Funari.
Pier Donato held the office of cleric of the Chamber, was granted the bishopric of Narni in commendam on 25 June 1546, and resigned it in favor of Romolo C. on 12 July 1566; he was created cardinal on 7 May 1570 by Pius V. He was legate at Bologna in 1580. He died in the Curia on 29 Sept. 1586 and was buried at S. Maria della Vallicella.
Bartolomeo, b. c. 1565, held the office of general treasurer in the Curia, which led to his creation as cardinal on 5 Jan. 1596. He was archbishop of Conza on 10 Mar. 1608, resigned in 1614; on 5 May 1621 he was given the see of Tivoli; however, he died the same year on 18 Oct. and was buried at S. Maria Maggiore.
General treasurer was also Pier Donato the younger, b. c. 1583, apostolic protonotary participant on 18 Apr. 1615, later created cardinal by Urban VIII on 16 Dec. 1641, camerlengo of the Sacred College on 9 Jan. 1651, died in the Curia on 30 Jan. 1656. A contemporary judged him: “in treasury matters he was tenacious, free in speech, of strong character, intelligent in business, moderately learned” (cf. Pastor, XIII, p. 716).
Greater fame among posterity was won by Federico, b. in Rome on 13 Mar. 1585 to Giovanni Federico, who was the brother of Card. Bartolomeo, and Olimpia Orsini.
Despite the ill-will of his father, who dissipated the ample patrimony and even alienated 102 pieces of antiquities from the family collection to Card. Ludovisi in 1622 (Pastor, XIII, p. 50), Federico remained steadfast in his love for literary and scientific studies, and on 18 Aug. 1603, together with Gian Franco Stelluti, Anastasio de Filiis, and Giovanni Eckio, he founded the Accademia dei Lincei, taking the name Coelivagus Lyncacus. Only in 1607 was Giovanni Battista Porta added as a fifth member; Galileo Galilei was the sixth and was officially received on 25 Apr. 1611 during his visit to Rome. Galilei himself informs us that “the Lincei are a company of scholars... and have as their aim the study of the liberal arts and in particular of philosophy and other sciences connected with it; moreover, they attend to the most learned in writing and publishing their labors” (Edizione Nazionale delle opere di G. Galilei, V, p. 184). Cesi became a friend of Galilei and maintained relations with him in the following years concerning the discoveries he was making and the controversies they aroused. Particular protection and favor were shown by Cesi to Galilei during his stay in Rome in 1615–16, defending the freedom of scientific inquiry. When it came to publishing a reply to the Libra astronomica of Fr. Grassi, Cesi, together with his colleagues, invited Galilei to publish the Saggiatore and promoted its printing, which appeared under the care of the Lincei themselves in 1623. They, in fact, almost in their entirety had embraced Galilei’s cause, though Cesi himself had only with difficulty converted to the Copernican system.
At Easter 1624 Galilei was a guest of Cesi at Acquasparta. He had, moreover, devoted himself to botanical research, in which he may be considered a true pioneer.
He had taken special care for the printing of Galilei’s Dialogo sopra i due massimi sistemi, when he died on 1 Aug. 1630 without having had male issue surviving from his two wives, Artemisia Colonna (married in 1614) and Isabella Salviati (married in 1616).
The Academy, whose membership had remained quite limited, entrusted to the care of its protector Card. Barberini, fell silent and soon ceased to exist.