Rings having 10 delocalizable electrons are of interest as potentially aromatic compounds. The unsubstituted 1,4‐dihydro‐1,4‐diazocine 1 has now been prepared by two independent syntheses. Some N,N′‐disubstituted derivatives of this ring system were already known. On the basis of its chemical behavior, spectra, and planar structure (confirmed by X‐ray structure analysis), 1 is to be regarded as a 10π aromatic species. No prototropic shift to give 2 or 3 is observed. The character of the N,N′‐disubstituted derivatives 4 is critically dependent upon the substituents. (Figure Presented.) Copyright © 1979 by Verlag Chemie, GmbH, Germany