Fantasy Setting: 2nd son prince is superfluous and a rogue

[Alan]

About 10 years ago, I was a regular visitor to my local library. During about a 2 year spree, I read a lot of fantasy books. My memory is quite poor, so here goes...

We meet this Prince (younger son) on a the top of a cliff where he is tossing daggers at a target while hanging upside down from a tree. He misses a shot and uses his trusty steed to retrieve the blade that went over the cliff. He is a roguish, superfluous kind of character.

There are 2 other parts that seem to try to include themselves into my memories of this book, but they could be from another book.

1) The main protagonist is another young lord, who has a Father in charge of a series of border forts. They visit these forts as part of the book. Eventually, this young lord meets the "superfluous prince."

2) In a desert land later on, this young lord finds an area with ancient obelisks covered in ancient runes. Eventually, these obelisks, triggered by magic, reveal a tower.

I know this is not much to go on, but I was hoping that here would be a good place to ask, after bugging my friends to no end.

Thanks for any efforts :)

- Al

[Lobstergirl, au gratin]

Alan, are you still looking for this or did you find it?

[Alan]

Sorry I took so long. I completely forgot about this question :)

No, I have not found the book title yet. My memory of it is so sketchy that I can't give good clues :)

[Kris]

A long shot - Blue Moon Rising by Simon R. Green? (via Worldcat)

Alan, is this book for teens (young adults) or older adults? Is there any romance?

How old is the prince? Can you describe his older brother or his parents?

Does the prince have special powers/abilities/skills?

Are there fantasy creatures? A great deal of magic?

[Alan]

Dang! Blue Moon Rising sounded so familiar, but when I read the excerpt here, there were no Unicorns in the book I'm trying to recall.

The Prince was a young man, in his twenties. He was very dexterous and coordinated. He was an expert with his throwing knives and quite knowledgeable about covert skills.

I don't think there were any fantasy creatures. None stand out in my muzzled memory, anyway. Magic was present, but not commonplace.

One thing I think I recall are 2 continents separated by a sea. The book's map had the continents' coasts equally running North/South with the sea being a dangerous trek, not often made.I could be mistaken on this part, though :)

Thanks for your suggestion and clarifying (hopefully) questions, though!