After Shoghi Effendi
When Shoghi Effendi died in 1957, Remey and the other Hands of the Cause met in a private Conclave at Bahjí in Haifa, and determined that he hadn't appointed a successor. During this conclave the Hands of the Cause decided that the situation of the Guardian having died without being able to appoint a successor was a situation not dealt with in the texts that define the Bahá'í administration, and that it would need to be reviewed and adjudicated upon by the Universal House of Justice, which hadn't been elected yet. Remey signed a unanimous declaration of the Hands that Shoghi Effendi had died "without having appointed his successor".
Three years later, in 1960, Remey made a written announcement that his appointment as president of the international council represented an appointment by Shoghi Effendi as Guardian, because the appointed council was a precursor to the elected Universal House of Justice, which has the Guardian as its president.
He also attempted to usurp the control of the Faith which the Hands had themselves assumed at the passing of Shoghi Effendi stating:
It is from and through the Guardianship that infallibility is vested and that the Hands of the Faith receive their orders...I now command the Hands of the Faith to stop all of their preparations for 1963, and furthermore I command all believers both as individual Bahá'ís and as assemblies of Bahá'ís to immediately cease cooperating with and giving support to this fallacious program for 1963.
He claimed to believe that the Guardianship was an institution intended to endure forever, and that he was the 2nd Guardian by virtue of his appointment to the IBC. Almost the whole Bahá'í world rejected his claim, although he gained the support of a small but widespread group of Bahá'ís. One of the most notable exceptions to accept his claim were several members of the French National Spiritual Assembly, led by Joel Marangella, who elected to support Remey. The Assembly was consequently disbanded by the Hands. The remaining 26 Hands of the Cause unanimously expelled him from the community. Remey himself declared that being the Guardian gave him the exclusive right to declare who was or wasn't a Covenant-breaker, and that those who opposed him and followed the Hands of the Cause were Covenant-breakers.
Read more about this topic: Mason Remey