Regular conferences of masons were held in Germany in the 1880s.
With the repeal of the Anti-Socialist Laws, it was possible to form legal trade unions, and at the 8th Congress of Masons, in Gotha, in May 1891, the Central Union of Masons was established.
[1] The union gradually built up international contacts in the late 19th-century.
In 1903, it called a conference in Berlin, to formalise these relationships by establishing the International Federation of Building Workers.
At the start of 1911, it merged with the Central Union of Construction Workers, to form the German Construction Workers' Union.