The Youngian Senate, also known as the Imperial Senate, Youngian Congress, or Imperial Congress, was the legislature of the Youngian Empire from 19-0 BMY.
The Youngian Senate was established in 19 BMY after the Youngian Empire by the self-appointed Youngian Emperor Larry Young, replacing the Galactic Senate of the Youngian Republic. Although at the time of the Empire's formation, the supermajority of senators were loyal to Young, the Youngian Senate was still a prime (and often clandestine) source of resistance to Young's authority, and despite it's modifications, came to be known as the "last remnants of the Old Republic".
In 0 BMY, Emperor Young ordered the Senate shut down "for the inefficency of it's organization", basically because several Senators began openly opposing Young's policies. It has been replaced indefinetely as the Imperial legislature by the Imperial Council of Ministers, which already was a executive advisory council: all references to the Senate in the Imperial Constitution were removed or modified.
Besides the name, its organization differed somewhat from its Republican forebear. Whereas the Galactic Senate had held both legislative and executive power, the Youngian Senate held legislative power (and even that held only in the Emperor's name) by orders of the Imperial Constitution. Despite such, it still held limited judicial authority, enough to try high ranking officials in the Empire and, possibly, handle cases tied into the Imperial Court (for as long as it lasted). The Senate could advise the Emperor, work on the Imperial budget, and pass laws in the Empire. However, the Emperor could introduce, veto, and pass Senate legislation, and both call and dismiss the Senate at will.
Because of the Sector Governors and Regional Governors, the Senators no longer served or had power as governor-delegates, which probably added to the dissolution of the legislature.
The Senate could pass amendments to the Imperial Constitution, and apparently had at least nominal oversight of the Imperial Military and government bureaucracy.
The day-to-day head of the Senate was no longer the Vice Chair, but the Prime Minister. The Senate was, at least in theory, responsible for choosing a new Emperor upon the death or abdication of the current holder of the throne.