Bishop of Basel; b. Montavon (Berne), Switzerland, Oct. 14, 1819; d. Balerna (Ticino), Nov. 1, 1886. After completing his philosophical and theological studies in Albano in Italy, he was ordained (1842) and then worked as a missionary in Italy until 1844, when he went to Alsace. In 1850 he became pastor in Grandfontaine (Berne), and in 1855, dean in Delémont. As bishop of Basel (1863–84), he headed the largest see in the seven cantons during a period of radicalism characterized by constant infringements on ecclesiastical matters. At vatican council i, Lachat spoke in favor of papal infallibility. As a result, the Swiss press violently attacked him. Open battle, the kulturkampf, broke out when Lachat inflicted ecclesiastical censures on the few priests who refused to admit the defined doctrine of papal infallibility. Lachat was declared deposed by the governments of five of the seven cantons in which his diocese lay (Jan. 29, 1873) and was expelled from his residence (April 16, 1873). For the next 12 years he directed his see from exile in Lucerne, where he erected a seminary (1882). At the wish of Pope leo xiii, he resigned his bishopric (1884). He was made titular archbishop of Damietta and apostolic administrator of Ticino (1885), and he erected a seminary in Lugano, where he was buried in the church of S. Maria degli Angeli.
Bibliography: p. vautrey, Histoire des évêques de Bâle, v.2 (Einsiedeln 1886) 559–635. d. ferrata, Mémoires, v.1 (Rome 1920) 69–184. j. folletÊte, Un Évêque jurassien (Paris 1925). t. schwegler, Geschichte der katholischen Kirche in der Schweiz (2d ed. Stans 1943). a. chÈvre, "Mgr. Eugène Lachat, évêque de Bâle: Á Propos d'un centenaire 1863–1963," Zeitschrift für Schweizerische Kirchengeschichte, 58 (1964) 119–133.
[j. b. villiger]