they were used for all types of warfare if you needed one you used one
for hurling items
People who died during the bubonic plague were usually placed in the handle of a giant cataput then launched to the other side of their wall.
this is only a few but...they used rosemary, spearmint,anise,sage,cinnamon,rue, and lastly myrrh. Hope this helps!
To engage the enemy from a distance.