1933

After accession to power by the National Socialists, Julius Dietz, a staunch NSDAP supporter, is appointed as the new foundation commissioner. The foundation statute is “politically” adapted without consideration of the founder's will. Among other things, the requirement enshrined in the statute of tolerance for heritage, denomination and party status of employees (§ 56) is abolished. Fierce arguments arise between Julius Dietz and the regional administration on one side and the management of the companies and individual brave citizens such as Abbe’s daughter Grete Unrein on the other. They culminate in a lawsuit against the Thuringian Minister of the Interior, Fritz Wächtler, because of the forced changes to the statute.

1945

American troops occupy Jena and the factories Zeiss and Schott. As they leave in June 1945, they take 122 key employees (scientists, engineers, the entire executive branch) and important documents with them to the West. Initially, the employees are detained in Heidenheim an der Brenz, and the documents are sent to the USA for evaluation.
15 November: Restoration of the statute that was valid before 1933.

1946

The Zeiss employees, who were transferred to the West, start building an optical factory in Oberkochen under the name Opton. Schott employees build a new factory in Mainz in 1951/52. In Jena, Zeiss and Schott are dismantled by the Russian military power to a negligible residual stock of 6%. Material and personnel are transported to the USSR.

1947

Renaming of “Opton Optische Werke Oberkochen GmbH” to “Zeiss Opton Optische Werke GmbH”.

1948

The Jena foundation companies are expropriated and converted to state-owned enterprises.
Opton is applying to the Baden-Württemberg government to relocate the registered office of the foundation to Heidenheim. This is granted in 1949 by the Ministry of Justice. At the same time, the local Carl Zeiss Foundation continues to exist in Jena.

1951

The Oberkochen company Opton renames itself to Carl Zeiss. Thus, from 1951 on, the organisation is split into the state-owned companies Carl Zeiss and Jenaer Glaswerk Schott & Gen in Jena as well as the foundation company Carl Zeiss in Oberkochen and Jenaer Glaswerk Schott & Gen in Mainz. Carl Zeiss Jena supports the development in the West by providing documents as well as experts. In return, Oberkochen and Mainz update Jena with new developments.

1953

Decision by the DDR government that in the future foreign trade may no longer be handled directly by Carl Zeiss Jena, but only through the German East/West Trade Organisation (DIA). Collaboration between Zeiss East and West is thus no longer possible. Shortly thereafter, 15 Jena Zeiss employees, who supported cooperation with the West, were arrested on suspicion of “sabotage and espionage”.

1954

The Carl Zeiss Foundation in Jena, the state-owned company Carl Zeiss Jena and the Carl Zeiss company in Oberkochen sue each other to stop the other party from using the trademarks and the word “Zeiss” in the company name.

1959

The executive boards of the companies Zeiss Oberkochen and Schott Mainz, who were the provisional foundation administrators during the transitional period, reactivate the foundation administration designated in the statute, which is now administered by the Ministry of Education and Cultural Affairs of the state of Baden-Württemberg. The Ministry of Education and Cultural Affairs appoints a foundation commissioner according to the statutes.

1971

In the so-called “London Agreement” there is a consensus on the worldwide use of trademarks. The negotiated compromise stipulates that everyone in their respective political hemisphere is allowed to use the name Carl Zeiss or Jenaer Glaswerk.