ky3PT‖Send to Back

H28NG‖Moves the selected object to the bottom of the stacking order, so that it is behind the other objects.

To access this command...

ebLJB‖From the menu bar:

t8dFS‖From the context menu:

4it9a‖Choose Arrange - Send to Back.

qBbLh‖From the tabbed interface:

xAyVd‖Choose Image - Send to Back.

PUnXv‖Choose Object - Send to Back

sXy2C‖From toolbars:

K5oKD‖Icon Send to Back

mH2tS‖Send to Back