Gebhard Truchsess von Waldburg (10 November 1547 – 31 May 1601) was the archbishop-elector of Cologne from 1577 to 1588. After pursuing an ecclesiastical career, he won a close election in the cathedral chapter of Cologne over Ernst of Bavaria. After his election, he fell in love with and later married Agnes von Mansfeld-Eisleben, a Protestant canoness at the Abbey of Gerresheim. His conversion to Calvinism and announcement of religious parity in the electorate triggered the Cologne War.
On 19 December 1582, a proclamation in his name established parity for Catholics and Calvinists in the Electorate of Cologne, causing a scandal in the Roman Catholic Church and the Holy Roman Empire, and after his marriage in February 1583, he sought to convert the electorate into a dynastic dignity. For the next six years, his supporters fought those of the Roman Catholic dominated cathedral chapter for the right to hold the electorship and the archdiocese in the so-called Cologne War or Seneschal War. After brutal fighting, and the plundering of villages, cities, and abbeys throughout the electorate, Gebhard surrendered his claim and retired to Strasbourg. He died there in 1601 and was buried in the Cathedral.
Gebhard's conversion and marriage was the first major test of the principle of ecclesiastical reservation established in the Peace of Augsburg, 1555. His loss of the electorate strengthened the Catholic Counter-Reformation in the northern German states, gave the Jesuits a stronghold in Cologne, and expanded the Wittelsbach family influence in imperial politics.
Gebhard was born in the Fürstenburg fortress of Heiligenberg, the second son of William, known as the younger, (6 March 1518 – 17 January 1566), Freiherr and Seneschal of Waldburg and an Imperial councilor, and his wife, Johanna v. Fürstenberg (1529–1589). His family was an old Swabian house and he was descended from the Jacobin line of the House: Jakob I Truchseß von Waldburg, also known as the Golden Knight (for his blond hair). The family owned extensive properties that bordered on the Abbey of Kempten and various Habsburg territories in present-day southwestern Bavaria; In 1429 and 1463, the three surviving sons of Johann II, Jakob, Everhard, and George, and their surviving sister Ursula, concluded a covenant of inheritance to protect the family property. In the future, they would occupy and own the property as one; the inheritance of the daughters could not exceed 4000 gulden. They guaranteed each other the right of first refusal on potential property sales.
Gebhard's grandfather had been a commander for the Swabian League army in 1531; a cousin of his grandfather, Jörg Truchsess von Waldburg, also known as Bauernjörg, had been a commander of the imperial army in the Peasant Wars (1525). His uncle, Otto (1514–73), was the bishop of Augsburg, later a Cardinal, and founded the University of Dillingen in Augsburg. His younger brother, Karl (1548–1593), trained for a military career; a second younger brother, Ferdinand, died at the siege at 's-Hertogenbosch in 1585.
As a younger son, Gebhard was prepared early for an ecclesiastical career. He received a broad, Humanist education, learned several languages, including Latin, Italian, French, and German, and studied history and theology. After studying at the universities of Dillingen, Ingolstadt, Perugia, Louvain and elsewhere, he began his ecclesiastical career in 1560 at Augsburg, serving as prebendary in the Cathedral church. His life at Augsburg caused some scandal; Uncle Otto, the archbishop, petitioned the Duke of Bavaria to remonstrate with Gebhard about his conduct, which apparently led to some improvement in his behavior. In 1561, he became a deacon at the cathedral in Cologne (1561–77), a canon of St. Gereon in Köln (1562–67), a canon in Strassburg (1567), in Ellwangen (1567–83), and in Würzburg (1569–70). In 1571, he became deacon of the Strassburg Cathedral, a position he held until his death in 1601. In 1576, by papal nomination, he became provost of the Cathedral in Augsburg. He would have drawn a stipend from all these positions.
In December 1577, he was chosen elector of Cologne after a contest with Ernst of Bavaria, the youngest brother of the ruling Duke. He won the election by two votes. Although it was not required of him, Gebhard agreed to be ordained a priest, which his predecessor had not done.
The initial years of his office were relatively uneventful. Gebhard continued some of the work of his predecessor, Salentin, chiefly in the reconstruction of the Arnsberg castle in Westphalia.
Gebhard is chiefly noted for his conversion to the reformed doctrines, and for his marriage with the reportedly beautiful Agnes von Mansfeld-Eisleben, a canoness of Gerresheim. After living in concubinage with Agnes for two years, he decided, perhaps by the persuasion of her brothers, to marry her, doubtless intending at the same time to resign his see. Other counsels, however, prevailed.
Encouraged by Protestant supporters, including several in the cathedral chapter, he declared he would retain the electorate, and in December 1582, he formally announced his conversion to the reformed faith and the parity of Calvinism with Catholicism in the Electorate and archdiocese of Cologne. The marriage with Agnes was celebrated on 4 February 1583, and afterward Gebhard remained in possession of the see. This affair created a stir in the Holy Roman Empire.
The clause concerning ecclesiastical reservation in the religious Peace of Augsburg was interpreted in one way by his friends, and in another way by his foes; the former held that he could retain his office, the latter insisted that he resign. Hermann von Wied, a previous prince-elector and archbishop had also converted to Protestantism, but had resigned from his office; Gebhard's predecessor, Salentin von Isenburg-Grenzau, had resigned from the office upon his marriage, necessary to perpetuate his house. Unlike his predecessors, Gebhard proclaimed the Reformation, in the style of Calvinism, from the cathedral, angering Cologne's Catholic leadership and alienating the cathedral chapter. He placed the evangelical confession on parity with the Catholic one; furthermore, Gebhard adhered not to the teachings of Martin Luther, but to those of John Calvin, a form of religious observation not approved of in the Augsburg conventions of 1555.
Anticipating events, Gebhard had collected some troops and had taken measures to convert his subjects to Protestantism. In April 1583, he was excommunicated by Pope Gregory XIII; the unsuccessful candidate of 1577, Ernst, who was also bishop of Liège, Freising and Hildesheim, was chosen as the new elector. Initially, Gebhard was supported by Adolf von Neuenar and his own brother, Karl, who commanded most of his troops. Although he sought assistance from several of the Lutheran princes of Germany, especially Augustus I, elector of Saxony, these princes were not enthusiastic to support Gebhard's cause; his association with the Calvinists was not to their liking. Henry of Navarre, later Henry IV of France, tried to form a coalition to aid Gebhard, but the only assistance which he obtained came from John Casimir, who took command of Gebhard's troops in the spring of 1583. Later that summer, after fruitlessly marching the troops up and down the Rhine, a process of intimidation, he disbanded his army to administer the Palatinate of the Rhine for his ten-year-old nephew, the new Elector Palatine, Frederick IV.
Ernst had the support of the previous Elector, now Salentin IX of Isenburg-Grenzau, Frederick, Duke of Saxe-Lauenburg, and, probably most important, several thousand Spanish troops hired by the pope. While representatives from the cathedral chapter, the seven imperial electors, the emperor, and the pope tried to resolve differences around the negotiating table, first in Frankfurt am Main, and then in Mühlhausen in Westphalia, the armies of both sides rampaged throughout the southern portion of the Electorate, called the Oberstift, plundering abbeys and convents, burning villages and small cities, and destroying crops, bridges, and roads. None of the combatants were prepared to commit their troops in a fixed battle; it was far more lucrative, and safer as well, to use them in a show of force, intimidating the peasantry, besieging walled towns and small cities, and limiting trade and the sale of food-stuffs in the marketplaces.