My dear father,
I do hope the accommodations at Cair Andros are sufficient. His Majesty wishes to emphasize the importance of reclaiming the lands of Calenardhon from the usurpers - as for myself, I am certain you will do your duty to our gracious liege.
As I am certain you are well aware, His Majesty's predecessor King Cirion invited the Northmen south to help him combat ravening Easterling hordes. They arrived rather too late to do any -good- as King Cirion and his men fought to the last man on the Field of Celebrant, but refused to leave our lands. While this is obviously an unacceptable situation, the decimation of the Northern Army left us unable to reclaim our birthright and send the barbarians packing back north where they belong. This situation has since been rectified, and the latest Corsair raids on our sea trade with the North-Kingdoms make it even more critical to open the roads to Arthedain. I understand Cardolan guards the roads west of Isen - you will only have to reclaim the citadel of Orthanc. Any of the renowned horses of the barbarian-folk should be captured or (if that becomes impossible) destroyed.
The alleged king of the rider-folk is one Theoden - he is of an age with you, about, but stricken with the infirmity of the lesser races. Certainly, were he wise, he would not attempt to command the ridiculous tariffs he does now. It is surmised that his son Theodred has assumed command in military matters, and his nephew Eomer is also to be watched. Another matter of concern is this Eomer's sister, who fights at his side - is any further proof needed of their barbarousness? Their 'royal' family's only nobility comes from their distant relationship with our own line, though such is an unfortunate embarrassment to us. And, of course, any related...lenience will be punished harshly at the King's pleasure.
The King also mentions that you and your knights are under the absolute command of the Crown Prince in this matter. While I am aware this is...nonstandard, Prince Boromir is a renowned warrior and I am certain he will take good care of you and, of course, my brothers.
The Tower watches,
-your loving son Amrothos Imrahilion, esquire to His Imperial Majesty Aran Denethor II