1. Prince Tiernan
A standard fairy tale prince, he is brave, strong, highly attractive, and not terribly bright. Given to the adventuring life, he is trying to rescue his chosen princess from whatever danger she is inevitably in so they might live happily ever after.
2. Prince Alard
Alard is the only son of a bitter and harsh king, and spends most of his time away from the almost-empty castle. A disappointment to his father and ignored by his lady love, he is prone to heroic pursuits, as an attempt to earn someone’s approval. Courageous and honorable, he is also very lonely.
3. Prince Cyril
This fellow is bookish and given to philosopy and bouts of morbid depression. After the death of his father and the subsequent remarriage of his mother, his already unbalanced mental state has degraded; he has developed an obsession with ghosts and death, and if not watched properly, could do himself (or others) harm.
4. Prince Nabil
The Merchant Prince is not technically royalty, but is generally accepted as such. His father is the master of an important trade monopoly, and the prince himself is a shrewd trader. With his money and his connections, it would not surprise many if he were to wed into royalty, and become a prince in truth.
5. Prince Hakon
For one reason or another, Hakon was lost as a small child- either kidnapped, or separated from his family by some disaster. He has no idea of his true heritage, and his family has thus-far been unable to locate him. However, it is not impossible that someone has discovered his identity, and does not wish him to claim his birthright.
6. Prince Jarlath
Poor Prince Jarlath is still young, and no where near ready to assume power. It’s just as well; he is kept so busy running pointless and deeply silly errands for his (probably insane) father that he hasn’t got the time to do much else. He’s a little frightened of his father, but mostly does as he’s told to humor the old man.
7. Prince Raj
Raj is a skilled sailor and rather adventurous. He will enthusiastically to risk his own life in order to improve the lot of his people (to the eternal worry of his father). Despite his tendency towards risky behavior, he is reasonably clever and usually has a plan of sorts. He will make a good leader, once he settles down.
8. Prince Arjuna
Arjuna has a secret: "he" is actually "she". She is the only child of a king in ill health, and conceals her gender to prevent conniving advisors and nobles from trying to manipulate and use her. She developed the habit as a child because she was presented to the court as a boy, and has carried the charade off ever since. She doesn’t really think of herself as a girl, and fortunately doesn’t have much of a figure to hide.
9. Prince Dmitri
Dmitri is remarkably compassionate for a prince, and cannot help but try to protect those weaker than himself. He will instantly leap to the defense of anyone in trouble without a thought for his own safety, much to the irritation of his guardians. He is a skilled warrior, and not unfamiliar with magic.
10. Prince Abidan
Abidan was, originally, an arrogant and fool-hardy man, who was given a position of command in his father’s army. Through his own poor judgement, the prince brought his kingdom to ruin. The shock of the experience greatly matured him. Now he is more or less in exile, trying to find a way to undo the damage and make amends.
11. Prince Fremont
For one reason or another (possibly as a result of his own actions), Fremont is under a nasty curse. It has made him moody and belligerent, and he often lashes out at people in a fit of temper. While those closest to him know of the curse and pity him, the general populace does not know and regards him as something of a monster.
12. Prince Ludlow
Ludlow is the youngest of four sons. His brothers all are better qualified to assume the throne when their father dies, and have better claims on it than he. He has no serious expectations, and spends his time hunting, fishing, and riding, and generally ignoring princely duties all together.
13. Prince Albrecht
Albrecht is a cold, cruel, arrogant man, accustomed to getting his own way in all matters. Those who stand between him and what he wants soon find themselves dead, or wish they were. He will stop at nothing to achieve his goals, and has a definite sadistic streak. He is an excellent hunter, and boasts that no quarry, man or beast, has ever escaped him.
14. Prince Fitzpatrick
Prince Fitzpatrick is something of a novelty among the well-born: he’s a confirmed adrenaline junkie. He finds life in the palace so inutterably dull that he takes up danger-sports to alleviate the monotony. The more likely he is to get killed, the better he likes it. He’s also discovered that his hobby has a way of keeping the court in a state of nervous tension, which is all to the better.
15. Prince Dominic
Although a grown (or mostly grown) man, Dominic has been coddled and "protected" by his neurotic mother his whole life. His friends and interests are carefully chosen by her, and she often forbids him from pursuing a particular course of action because it is "too dangerous." She has gone so far as to imagine illnesses that he has, despite what the court doctos say. He is very uncomfortable with his mother’s obsessive doting, but lacks the force of will to say so. He is very shy and submissive, and doesn’t know how to act around people he doesn’t know.
16. Prince Alfred
When Alfred was a small child, he suffered from a terrible fever. He survived his illness, but the damage was done. He is quite mad, and kept hidden away from people in a secluded wing of the castle. When encountered, he is usually babbling incoherently, talking to people no one else can see. Typically, he is docile, but does have periodic fits of rage, and is strong enough to seriously hurt someone.
17. Prince Thanos
Thanos is profoundly and vocally devout. The only problem is, the prince’s religion is something wildly different from the state religion. He often criticizes the current order, pointing out logical flaws or dogmatic inanities. He has said, loudly and often, that when he comes to the throne there will be a lot of changes, starting with completely revamping the priesthood. His views make many people, the clergy especially, very nervous.
18. Prince Sayed
According to him, Sayed has done it all and seen it all. He has fought monsters, rescued damsels, found legendary treasures, and seduced fairy queens. He has done everything that anyone else has done better. The truth is, he’s never set foot outside the royal park. His continual one-upsmanship irritates many people, and his boasting is at the core of many diplomatic tensions. No one’s challenged him yet, but it is uncertain how he will react when it happens.
19. Prince Ulman
Ulman is a dyed in the wool coward, to a point bordering on paranoia. He’s afraid of everything and anybody he doesn’t know (given his temperment, this includes almost everyone). He refuses to set foot outside for fear, and has been known to flee screaming from something as harmless as a spider. His actions embarass the whole court, particularly his family, and they consider it just as well that he mostly stays locked in his rooms.
20. Prince Herbert
To the eternal shame of his father (a bona-fide war hero), Herbert does not quite… measure up. His appearance and manner is a trifle effeminate, and his interests are even less manly. When the "real men" of the court are hunting or carousing, he would prefer to be painting or composing music. He prefers the company of the ladies of the court to that of the men, and can gossip as well as any of them. Herbert’s father has spent most of the boy’s life trying to find excuses to pack him off to distant relatives or allies so as to spare himself further humiliation.
21. Prince Nicolai
Nicolai is very sympathetic to the plight of those less fortunate than himself, which is, naturally, everyone. He has a habit of slipping out of the castle late at night, disguising himself as just another commoner. He then spends a good deal of time listening to what the peasants have to say, their complaints and their desires. When he returns to the castle, he tries to nudge royal law to accommodate what he hears. Sometimes he gets his way, sometimes not.
22. Prince Mikael
This young man is king in all but name. His parents are either ill and bedridden, or dead, and the kingdom is politically unstable for one reason or another. Mikael spends most of his time frantically rushing around trying desperately to attend to the duties he is unprepared for. So far, he’s kept going from sheer momentum, but that can only last so long.
23. Prince Adon
He can have any woman he wants, and usually does. He is witty, charming, and dead sexy. At court, he is always surrounded by a dozen single ladies, who giggle and flirt with him and constantly jockey for position with each other. His personal magnetism keeps them distracted enough that they don’t openly fight amongst themselves in his presence, but there is a lot of cattiness and backstabbing when he’s not around. He’s the type that spends the night in a different bedroom every night, and never in his own.
24. Prince Oleg
Oleg is a smarmy, unpleasant man, constantly scheming against practically everyone else at the court. He was the second of three sons, but his two brothers died; one was poisoned at his nineteenth birthday feast, another was found stabbed to death in his rooms. The prince has not outright admitted his guilt, but then, he did not need to. He spends most of his time creating instabilities in the court (naturally in his favor) and waiting for his aging father to die.
25. Prince Tobias (Toby)
Toby is still a baby or a toddler; four years old at the most. However, his father suffers from a chronic illness, and his mother died when he was born. The prince has no other siblings or close cousins who could inherit, and he is expected to be a king before his next birthday. There is much competetion amongst various members of the court as to who will be Regent when the king passes away; the young prince is peacefully oblivious to the courtly intrigue, and wants only to play with his toys.
26. Prince Elias (and Prince Mica)
In a land where the king’s eldest son inherits the throne, the identical twins Elias and Mica pose something of a difficulty. Or they would, if they had not discovered as children that very few people can tell them apart. They have developed a habit of taking turns being Crown Prince Elias; while one attends to matters of the court and princely duties, the other is somewhere else quietly goofing off as Prince Mica. Most of the court knows the king has two sons; the twins have learned some minor skill at altering their appearances so as to keep their secret. They see no reason to change their ways when they ascend to the throne.
27. Prince Vladimir
Vladimir spent most of his adult life with the expectation that he would take the throne when his father died. He patiently waited. And waited. And waited. He is now well into middle-age, and his father is still tenaciously hanging on to life. The prince is extremely frustrated by this, particularly since there has been some talk among the advisors about how it might be better if they convinced the king to pass the crown to a younger heir, bypassing the prince entirely.
28. Prince Adir
Adir would have preferred to enter the priesthood; he has always been deeply religious, and considers the tenets of the faith to be unbreakable laws. However, his parents refused to allow him to become a priest, so he has contented himself with supporting the church and living his life as the faith decrees. He is seen as a saintly figure by other members of the religion, and there is some talk of canonizing him. If he ascends to the throne, he will be a staunch champion of the faith and will run the kingdom according to his religion.
29. Prince Padraic
Either as a diplomatic move, or because he was sent to live with distant relatives, Padraic was raised in a foreign kingdom. He has just recently returned to the land he was born in, but is a stranger. He speaks with an accent (if he speaks the language at all), he follows strange customs, and he has very little idea of the political situation. There is some talk that he feels more loyalty to his adopted country than this one, and he has been trying to create or strengthen diplomatic and commercial ties between the two. He doesn’t fit in at all, and he knows it.
30. Prince Odolf
Odolf was once a gifted athlete; he was strong, fast, and agile, and had his kingdom been at war with anyone, he would have made an excellent fighter. However, during a race with some of his friends, the prince’s horse was bitten by a snake, and rolled over him. He was crippled, almost entirely losing the ability to walk. Rather than becoming depressed over the loss of his physical abilites, he started developing his mental ones. He has found he enjoys studying, and is becoming something of a scholar.
(Thanks to Wulf for helping me come up with the last few.)