Sigismund was a son of Ulrich von Kollonitsch and was supported by his uncle, the Cardinal Prince-Primate of Hungary and Archbishop of Gran (Esztergom),
Leopold Karl von Kollonitsch. After attending the
Jesuit Convocation in
Neuhaus (
Bohemia), he studied at the German College of Apollinaris in
Rome and received his doctorate in theology. On 22 October 1699, he was ordained a priest, already a canon in Gran (Hungary) by 1700, and was consecrated titular
Bishop of Scutari. From 1705, he was a Royal Hungarian Councillor and, from 14 October 1709,
Bishop of Waitzen, where he founded the
Piarists. On 1 July 1716, he became the
prince-bishop of Vienna. Together with
Emperor Charles VI he petitioned
Pope Clement XI to elevate Vienna to an archdiocese. The
Prince-Bishop of Passau,
Raymund Ferdinand von Rabatta, tried to prevent this, but on 6 March 1721, the Congregation in Rome agreed, and on 1 June 1722, the decision of the
Consistory of Cardinals followed. On 14 February 1723, was that of
Pope Innocent XIII in signing the Papal Bull
Suprema dispositione, finally elevating Vienna. Kollonitsch then held the title of prince-archbishop, to whom the diocese of Wiener-Neustadt has been subordinated as suffragan. In 1729, the Viennese diocesan area was extended, when the area
Under the Wienerwald (the parishes between Vienna and Wiener-Neustadt) was separated from the diocese of Passau. He was elevated to the cardinalate by
Pope Benedict XIII on 26 November 1727, and at the same time appointed cardinal-priest of
Santi Marcellino e Pietro, in 1740 Kollonitsch changed to the titular church and became cardinal priest of
San Crisogono. As early as 1747, he had been awarded the title
Protector Germaniae by
Emperor Francis I. He was a zealous bishop who demanded of his priests participation in annual retreats and the wearing of clerical clothing. In 1719, he also introduced retreats for lay people. He increased the funds available for the creation of priests in St. Barbara and St. Stephan. In 1727, he acquired a palace in
Wien-Landstraße, which he had converted into a poorhouse; this was enlarged in 1784 and adapted to the
Invalidenhaus. In 1730, he conducted a general visitation of his diocese. He also won the lawsuit with the cathedral chapter of St. Stephen, when the Pope gave him jurisdiction over the canons. In return, he raised in 1728 the cathedral provost,
Joseph Heinrich Braitenbücher, to Vicar-General and Auxiliary Bishop. Being the last of his family, he adopted in 1728 the son of the half-sister of his father
Ladislaus Zay von Csömör. He appointed him heir to his dominions with the condition that he and all his descendants, with the complete omission of their former name and coat of arms, should be addressed only as Counts and Countesses von Kollonitsch. He is buried in the episcopal tomb of
St. Stephen's Cathedral in Vienna. ==Bibliography==