Germany's three longest-serving post-war Chancellors have all come from the CDU, more specifically: Helmut Kohl (1982–1998), Angela Merkel (2005–2021), and Konrad Adenauer (1949–1963).

Immediately following the end of World War II and the foreign occupation of Germany, simultaneous yet unrelated meetings began occurring throughout the country, each with the intention of planning a Christian-democratic party.

In the Cold War, years after World War II up to the 1960s (see Vergangenheitsbewältigung), the CDU attracted conservative, anti-communist, former Nazis as well as Nazi collaborators into its higher ranks (like Hans Globke and Theodor Oberländer but also future CDU chairman and West German chancellor Kurt Georg Kiesinger).

The result of these meetings was the establishment of an inter-confessional (Catholic and Protestant alike) party influenced heavily by the political tradition of liberal conservatism.

[14] The CDU experienced considerable success gaining widespread support from the time of its creation in Berlin on 26 June 1945 until its first convention on 21 October 1950, at which future West German Chancellor Konrad Adenauer was named the first Chairman of the party.

The latter was more nationalist and sought German reunification even at the expense of concessions to the Soviet Union (USSR), depicting Adenauer as an instrument of both the Americans and the Vatican.

The Western powers appreciated the CDU's right-ward slant, its commitment to capitalism, and its value as a pivotal oppositional force to the communists, thereby keeping consistent with US/UK foreign policy.

The durable alliance that the party had established with the liberal Free Democratic Party (FDP) as the leading tandem of several federal governments, and, implicitly, the strong partnership between Chancellor Adenauer and President Theodor Heuss enabled West Germany to thoroughly rebuild itself in the wake of World War II.

[16] As the Free Democratic Party (FDP) withdrew from the governing coalition in 1966 due to disagreements over fiscal and economic policy, Erhard was forced to resign.

The SPD quickly gained popularity and succeeded in forming a social-liberal coalition with the FDP following the 1969 federal election, forcing the CDU out of power for the first time in its history.

Although Kohl was re-elected, the party began losing much of its popularity because of an economic recession in the former GDR and increased taxes in the west.

In the 1998 federal election, the CDU polled 28.4% and the CSU 6.7% of the national vote, the lowest result for those parties since 1949; a red–green coalition under the leadership of Gerhard Schröder took power until 2005.

In the 2002 federal election, Merkel ceded the position of CDU/CSU's joint candidate for the chancellor's office to the leader of the sister party, Bavarian minister-president Edmund Stoiber.

CDU and CSU polled slightly higher (29.5% and 9.0%, respectively), but still lacked the majority needed for a CDU–FDP coalition government and stayed in opposition.

CDU candidate Christian Wulff won the 2010 presidential election in the third ballot, while opposition candidate Joachim Gauck (a Protestant pastor and former anti-communist activist in East Germany, who was favoured even by some CDU members) received a number of "faithless" votes from the government camp.

The decisions to suspend conscription (late 2010) and to phase out nuclear energy (shortly after the Fukushima disaster in 2011) broke with long-term principles of the CDU, moving the party into a more socially liberal direction and alienating some of its more conservative members and voters.

[22] Psephologist and Merkel advisor Matthias Jung coined the term "asymmetric demobilisation" for the CDU's strategy (practised in the 2009, 2013 and 2017 campaigns)[23] of adopting issues and positions close to its rivals, e.g. regarding social justice (SPD) and ecology (Greens), thus avoiding conflicts that might mobilise their potential supporters.

In October 2018, Merkel announced that she would step down as leader of the CDU that December and not seek reelection, but wanted to remain as Chancellor until 2021.

Kramp-Karrenbauer was considered Merkel's ideological successor, though holding more socially conservative positions, such as opposition to same-sex marriage.

However, the EPP group ultimately nominated the CDU's Ursula von der Leyen as their candidate for President of the European Commission; she was elected in July 2019, becoming the first woman to hold the office.

While the Thuringia crisis was the immediate trigger for Kramp-Karrenbauer's resignation, she stated the decision had "matured some time ago",[34] and media attributed it to the troubled development of her brief leadership.

[35] Kramp-Karrenbauer remained in office as Minister of Defence and interim party leader from February until the leadership election was held in January 2021.

Merkel and Bundestag President Norbert Lammert have been keen to clarify that CDU references to the "dominant culture" imply "tolerance and living together".

As a conservative party, the CDU supports stronger punishments of crimes and involvement on the part of the Bundeswehr in cases of domestic anti-terrorism offensives.

The party calls for EU member states to limit their annual borrowing to three percent of their gross domestic product.

The CDU has an official party congress adjudication that prohibits coalitions and any sort of cooperation with either The Left or the Alternative for Germany.

In the eastern federal states, however, there is ongoing tolerance for, or cooperation of CDU with, the right-wing radical AfD at the local and district level.

[47][48][49] CDU leader Friedrich Merz took blowback for his political approaches to the AfD after he called his party in 2023 an "alternative... with substance".

The foreign associations recognized by the federal executive committee each send a delegate to the party congress, regardless of their number of members.

The most notable and serious such incident was in 1976, when the CSU under Franz Josef Strauß ended the alliance with the CDU at a party conference in Wildbad Kreuth.