See also Attacking Valleys, NPCs vs Ballistae
If the target was an NPC city or valley include the level that it was.
Your technology levels for:
Military Tradition
Iron Working
Compass
Horseback Riding
Archery
Medicine
If it wasn't an NPC please include technology levels of the defending player if possible.
The same as above. If it was a city also include the Engineering level.
The attack of the Hero you used
Also, if you know the attack of the defending hero include it. If you attacked a player this can be found by clicking "Statistics" in the bottom left, then searching for the hero by name and owner. If you attacked an NPC you would only gain this information if you took the hero captive.
Lastly include a link to the battle report.