Ludwig Kaas (23 May 1881 – 15 April 1952) was a German Roman Catholic priest and politician of the Centre Party during the Weimar Republic.

In 1916 he published the book "Ecclesiastical jurisdiction in the Catholic Church in Prussia" (Die geistliche Gerichtsbarkeit der katholischen Kirche in Preußen in Vergangenheit und Gegenwart mit besonderer Berücksichtigung des Wesens der Monarchie), demonstrating his expertise in church history, Canon law and his political interests.

In 1923, a year of crisis, he – just like Konrad Adenauer, then mayor of Cologne – fought the separatists that wanted to break away the Rhineland from Germany.

In view of this new position, he asked Cardinal Adolf Bertram of Breslau, to provide him with experts who might serve as a link between the Nuncio in Munich and the Prussian bishops.

Bertram suggested Kaas, who in his academic work had developed a special interest in the relations between the state and the Catholic Church.

In 1922 he was prepared to resign his chair, but Bertram and Pacelli insisted that he should stay until he had obtained a secure position within the diocese that would not hinder his external commitments.

[3] Bishop Bornewasser had allowed Kaas to keep his parliamentary seat until September 1924, but expected him to resign it afterwards and concentrate on his administrative and academic work within the diocese.

However, Pacelli asked the bishop not to insist on this as it would "substantially hinder the hitherto influential work of Dr. Kaas and damage an effective representation of ecclesiastical interests in a deplorable way".

Nonetheless, Kaas would frequently travel to Rome, where he would stay with Pacelli, and experience first hand the conclusion of the Lateran Treaty, which he penned an article on.

As his frequent Vatican travels hampered his work as chairman, Kaas was prepared to yield the leadership of the party to Brüning, whom Hindenburg had dismissed in May, but the former Chancellor declined and asked the prelate to stay.

Later that month, from 15 March, he was the main Centre Party advocate supporting the Hitler administration's Enabling Act[1] in return for certain constitutional and, allegedly[11] ecclesiastic guarantees.

[citation needed] A considerable group of parliamentarians however opposed the chairman's course, among whom were the former Chancellors, his nemesis Heinrich Brüning and Joseph Wirth and former minister Adam Stegerwald.

The proponents however argued that a "national revolution" had already occurred with Hitler's appointment and the presidential decree suspending basic rights, and that the Enabling Act would contain revolutionary force and move the government back to a legal order.

Both groupings were not unaffected by Hitler's self-portrayal as a moderate seeking co-operation, as given on the Day of Potsdam of 21 March, as against the more revolutionary SA led by Ernst Röhm.

Hitler's speech, which emphasised the importance of Christianity to the German culture, was aimed particularly at assuaging the Centre Party's sensibilities and almost verbatim incorporated Kaas's requested guarantees.

Kaas gave a speech, voicing the Centre's support for the bill amid "concerns put aside", while Brüning notably remained silent.

When parliament assembled again in the evening, all parties except the SPD, represented by their chairman Otto Wels, voted in favour of the Enabling Act.

[citation needed] Kaas had planned to travel to Rome since the beginning of the year, to discuss a conflict in Eupen and Malmedy, formerly German towns now belonging to Belgium, where priests had been arrested.

Papen officially went on skiing holidays to Italy, but his real destination was Vatican City, where he was to offer a Reichskonkordat on his government's behalf.

These discussions also prolonged his stay in Rome and raised questions in Germany as to a conflict of interest, since as a German parliamentarian he was advising the Vatican.

On 5 May Kaas resigned from his post as party chairman, and pressure from the German government forced him to withdraw from visibly participating in the concordat negotiations.

Even before the Roman negotiations had been concluded, the Centre Party yielded to increasing government pressure and dissolved itself, thus excluding German Catholics from participating in political life.

The Centre Party's vote for the Enabling Act, at Kaas's urging, was an action which fostered the establishment of the Hitlerian tyranny.

[16] Kaas, who had played a pivotal role in the concordat negotiations, hoped to head an information office, watching over the implementation in Germany.

Late in that year, after the outbreak of World War II, Kaas was one of the key figures for the secret Vatican Exchanges, in which Widerstand circles within the German army tried to negotiate with the Allies through the mediation of the Pope Pius XII.

At the Christmas message of the Holy Year 1950, Pius XII presented the preliminary results, which deemed it likely that the tomb of Saint Peter was resting below the Papal altar of the Basilica.