A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 24 April 2014
If I create multiple attack phases by either using Retibution after my opponent uses Retibution or by using 2 Reprisals (either being down 2 provinces, or just down one and failing to take from the first Reprisal) would attacking into the same province count as the same Battlefield for the sake of Back to the Front?
Relevant text: Absent Battle: Target your personality at any location that assigned to this battlefield (this turn) move him there and straighten his unit as he moves.
The wording of Back to the Front seems to suggest that it would be considered the same battlefield by specifying (this turn).
Jon Palmer (rules official), 24 April 2014
If I create multiple attack phases by either using Retibution after my opponent uses Retibution or by using 2 Reprisals (either being down 2 provinces, or just down one and failing to take from the first Reprisal) would attacking into the same province count as the same Battlefield for the sake of Back to the Front?
Relevant text: Absent Battle: Target your personality at any location that assigned to this battlefield (this turn) move him there and straighten his unit as he moves.
The wording of Back to the Front seems to suggest that it would be considered the same battlefield by specifying (this turn).
Nope. A new battlefield is created every time an attack phase starts (or in certain other situation), and the battlefields go away when the phase ends.
From the CR - "Even though a subsequent attack or effect may create a battlefield associated with the same Province as a previously existing battlefield, the new battlefield is a different area from the old battlefield."