In medieval times, did they have heralds who observed battles, decided who won, and gave names to the battles?

Question

Were these heralds an international corporation of experts who regulated civilized warfare?

Answer 1

The heralds were not international - each side had their own (though you may be sure that the heralds of each side compared notes with each other as necessary).

The job of the herald was to convey challenges etc before the battle and to identify casualties (well, high-ranking casualties, anyway) afterwards.  They were not referees in any sense - it was usually pretty obvious at the end of the day who'd won and who'd lost.

As for names of battles - these have sorted themselves out over the centuries without too much outside help.  Usually the winner chooses.

Answer 2

There were to some extent medieval "war corespondents", they were priests that wrote up the events. They tended to be at the battle to record an individuals exploits or to give the last rites to the dying.

Winners were usually decided by the death, capture or the retreat of one army of the leader of that army. Battles were usually named after the area or nearest major geographical feature they took place in or by (Nazeby, stirling bridge etc.)

The concept of "Chivalry" was the process that regulated warfare.  Certain things were expected in battle. A lord could possibly expect to be ransomed if captured, but a peasant was considered worthless and sometimes were executed.  But sometimes (especially if he'd made enemies) a lord would be singled out in revenge (effectively a grudge match).