window last

This operation is for split windows. The corresponding operation for hidden windows is window swap last.

Each screen has a current window and a last window, where the last window is the window that was most recently the current window.

This operation makes the last window the current window, and the current window the last window.

A screen might not have a last window if you have removed the last window from the screen with window hide or window kill or anything like that. If a screen does not have a last window, then the top window on the screen is the last window.

If the current window is the top window, and the screen does not have a last window, then this operation does nothing.

If you have three split windows on a screen, 1, 2, and 3, and window 2 is the current window, and you switch to window 3, window 2 is the last window and window 3 is the current window. If you do window last then window 3 is last window and window 2 is the current window.