A continuous, azimuthally rotating, detonation wave propagating between the confines of a narrow annulus has been the essence of the Rotating Detonation Combustor (RDC) mechanics, till date. This research, however, focuses on the incipient RDC concept that utilizes a hollow combustor for the sustained rotating detonation, instead of the conventional annular combustor. Hydrogen-Air operation is demonstrated in a hollow RDC (H-RDC). The concomitant detonation wave speeds are upwards of 90% of the ideal Chapman-Jouguet speed at rich conditions of operation. While the H-RDC is prone to two wave operation for all the air flow rates tested, highly rich conditions produce solely single wave operation. High-speed video imaging of the H-RDC exit highlights the presence of a complex detonation structure comprising a relatively faster detonation wave that moves along the combustor wall, and a sectoral region of intense combustion that rotates with the same angular velocity. The pressure profile of the operating points is analyzed to reveal three different waveform shapes which are further analyzed using ensemble averaging. A peculiar instability observed for select operating conditions is discussed.