TAU

The Trans-Atlantic Union, commonly known as TAU, was a supranational entity formed in 2061 from the union of the European Federation, Anglic Union and the USA. It was the precursor of the First Commonwealth and by extension the Terran Republic. During its entire existence, it was under a de facto military dictatorship led by the Custodian. In 2072, the Union and all of its constituencies were dissolved and absorbed into the new First Commonwealth. Its de facto capital was Brussels. 
In contrast to its name, TAU did not correspond to the Atlantic's coastline. From its inception, it encompassed Oceania (previously a part of CANZUK), Siberia, most of the Middle-East and mainland China. Additionally, during the decade it existed, it expanded substantially as part of the Unification Wars, invading Latin America in the late 2060s and Sub-Saharan Africa in the early 2070s. India, the Japan-Korea Union, East African Federation and Taiwan are some of the countries which willingly joined the Union following its creation. By 2072, it had grown to encompass nearly the entirety of	Earth, whilst both Martian and Lunar colonies willingly submitted to its overlordship.
Despite its nominal status as a supranational confederacy of equal and willing members, the Union was dominated throughout its existence by EUFED and specifically the Custodian. Although officially they joined willingly, both the USA, weakened by the decades-long Second Civil War, and CANZUK were in effect threatened into joining the Union by the Custodian. Other members which willingly joined, with the exception of Taiwan and the East African Federation, did so under similar circumstances. The initial unpopularity of the new regime lead to many guerrilla movements and uprisings, most of which were crushed through military means. The regime would only become more popular in the 2080s after the reform into the First Commonwealth, when substantial economic and environmental benefits became apparent.