1 He claims that the Third Estate is essentially the Nation. 2  June 17, 1789. 3  Accepting the proposition of the delegate Abbe AbbÃ©, sieyes SieyÃ¨s The third estate Proclaims Itself The.. 4  National assembly it invites the Other two orders to join in this new body of.  the nation This body came into being on 17 June 1789, with the renaming of the Estates-General on the motion of the abbe AbbÃ©. 2  Sieyes sieyÃ¨s the renaming was effectively a claim that this new body was. 3  Now, sovereign initially it comprised the members Of The third estate and a few liberal nobles.  and clergy