Why was Merry at the last battle?

[Gordis]

Originally Posted by Lariren Shadow

As for Aragorn(which I now have to look at to make sure its spelled right, damn Tudor history) beheading the Mouth of Sauron, he needed to die. Who else better to kill him than Aragorn? Plus, as it has been said, it's the movie, it looks good.

Sorry... but it looks AWFUL. It was during the PARLEY, for Christ's sake! If you kill an enemy ambassador during a parley, then you are no better then an Orc. In fact, you are worse. Even Orcs knew the rules, see what they cried to Aragorn when he stood above the gates in Helm's Deep:

'Get down or we will shoot you from the wall,' they cried. 'This is no parley. You have nothing to say.'-LOTR, Helm's Deep

In the Books, the Mouth came forth, secure in his belief in Gondor's honor. And he was not mistaken:

‘I am a herald and ambassador, and may not be assailed!’ he cried.
‘Where such laws hold,’ said Gandalf, ‘it is also the custom for ambassadors to use less insolence. But no one has threatened you. You have naught to fear from us, until your errand is done- LOTR, The Black Gate opens.

The Movie Mouth was a naive guy, trusting the wannabe King (who only won the crown by bringing the green jelley to the Plennor) and the ragtag wizard (who so dearly loved to beat mad Denethor on the head with his staff). No wonder the Mouth got his head chopped off in the most treacherous fashion.