In The Thousand Isles, the Interregnum was the approximately two hundred year period of general political instability and economic decline that followed the sudden withdrawal of the Annwyn Empire from the region.
The Interregnum is generally considered to have started in IY 723 when The Recall order was received in Haven Towne and is generally judged to have ended in IY 902 when the entirety of Bonny Isle came under the control of the The Republic of Haven.