The Batavia (or Tertiary) Excession was the third recorded macroexcession, centered near the village of Batavia, Suriname. It unrolled the seventh spatial dimension (and fourth inferior dimension), later named the Cerulean Dimension, and the first found to contain sentient non-human lifeforms.
Though originally believed to be related to an accident at the South Atlantic Teracollider, the Batavia Excession was later confirmed to be spontaneous. In 25 AK, Eustace Jenkins was able to show that the timing and observed effects of the Batavia Excession -- as well as those of the Event (or Primary Excession) and the Secondary Excession -- were consistent with the Degeneration Theory.
The Batavia Excession is widely considered to have been the "point of no return" at which the collapse became inevitable. It is also marks the end of the pre-Adda Krazh calendar, since "after" the Batavia Excession, anachronisms became so frequent and widespread as to render the notion of linear timekeeping untenable. It occurred on January 17, 2091.