How did Rhaegar and Arthur become friends?

[Bael's Bastard]

I see no reason to assume that there was another living Dayne male between Lord Dayne and Arthur. It might be slightly presumptuous to call Arthur the second son, but there is no hint of another Dayne sibling.

Rhaegar's great-great grandmother was Dyanna Dayne, who had six children, including two daughters whose marriages and children we have no further information about. More recently, the Martell mother of Doran, Elia, and Oberyn spent time at court as a girl with Joanna Lannister as a companion of Princess Rhaella. We know Joanna was there for a few years after Rhaegar was born, starting when Jaehaerys was crowned in 259. In 270, King Aerys visited Sunspear. About a decade later, Ashara Dayne came to court as a companion of Elia Martell. So it seems there was no shortage of contact between the Targaryens and the Dornish during Rhaegar's lifetime.

I wouldn't be surprised if Arthur was sent to court in his youth, though that is very speculative. It could be as simple as them meeting and hitting it off at a tournament somewhere, whether in King's Landing or elsewhere.

I think the earliest mention of Rhaegar and Dayne together is the tournament in Lannisport to celebrate the birth of Viserys in 276. Rhaegar was newly knighted, and fell to Ser Arthur Dayne, who is described there as "the renowned Kingsguard knight." It is not clear if this is stating that Dayne was already in the KG and renowned when he faced Rhaegar in 276, or if this is a statement taking into account his whole life.

But I suppose it is even possible that they met for the first time and became friends at that tourney. It seems a little odd that Rhaegar's oldest friend would be made when he was already seventeen, but considering Rhaegar, I guess it wouldn't be extremely odd.

[Romaine3]

45 minutes ago, Bael's Bastard said:

I see no reason to assume that there was another living Dayne male between Lord Dayne and Arthur. It might be slightly presumptuous to call Arthur the second son, but there is no hint of another Dayne sibling.

Rhaegar's great-great grandmother was Dyanna Dayne, who had six children, including two daughters whose marriages and children we have no further information about. More recently, the Martell mother of Doran, Elia, and Oberyn spent time at court as a girl with Joanna Lannister as a companion of Princess Rhaella. We know Joanna was there for a few years after Rhaegar was born, starting when Jaehaerys was crowned in 259. In 270, King Aerys visited Sunspear. About a decade later, Ashara Dayne came to court as a companion of Elia Martell. So it seems there was no shortage of contact between the Targaryens and the Dornish during Rhaegar's lifetime.

I wouldn't be surprised if Arthur was sent to court in his youth, though that is very speculative. It could be as simple as them meeting and hitting it off at a tournament somewhere, whether in King's Landing or elsewhere.

I think the earliest mention of Rhaegar and Dayne together is the tournament in Lannisport to celebrate the birth of Viserys in 276. Rhaegar was newly knighted, and fell to Ser Arthur Dayne, who is described there as "the renowned Kingsguard knight." It is not clear if this is stating that Dayne was already in the KG and renowned when he faced Rhaegar in 276, or if this is a statement taking into account his whole life.

But I suppose it is even possible that they met for the first time and became friends at that tourney. It seems a little odd that Rhaegar's oldest friend would be made when he was already seventeen, but considering Rhaegar, I guess it wouldn't be extremely odd.

Everything you say here leads me to believe that they had to have met earlier in their lives as children. Both died at very young ages. Granted, Rhaegar was melancholy and a bit of a loner, he also went through his nerd phase early on.

This is why I believe that when Rhaegar began to show interest in developing his martial skills, Arthur was brought in to train and develop alongside of him. Their friendship bond was forged in training together. My guess is no earlier than 11 or 12 & no later than 14. The earlier the better though, it seems unlikely that one can become a "puissant" warrior (Ser Barristan's word for Rhaegar) in a 2 year time span.

[Hangover of the Morning]

16 hours ago, PrettyPig said:

Nothing in text yet to support this notion, but it certainly seems that many friendships/alliances were forged during the War of the Ninepenny Kings:  Aerys/Tywin, Hoster Tully/Littlefinger's father, etc., so  I wouldn't be surprised to learn that Aerys and Lord Elder Dayne (Arthur's father) were also thrown together at this time.  

I mean, the Stepstones are right there in Dorne's backyard; it seems reasonable that the Daynes would have a dog in that fight.

That's an incredibly astute observation and definitely a possibility. It wouldn't even have to be Aerys who Papa Dayne got close to during the war but just someone influential at court. 

[PrettyPig]

5 hours ago, Hangover of the Morning said:

That's an incredibly astute observation and definitely a possibility. It wouldn't even have to be Aerys who Papa Dayne got close to during the war but just someone influential at court. 

Yeah, and even though we don't have any textual references for it, the timeline fits and it makes sense.   GRRM is clearly holding his House Dayne cards close to his chest, so perhaps in the next book(s)   we'll get the backstory on how the Crown and the Daynes came together.   WotNPK seems to be where many other noble houses came together though, so I'll keep that as my unofficial headcanon for now.

[SFDanny]

I like to think of it as the result of a wild lost weekend in Lys. What happens in Lys stays ...

Fill in the lurid details.

[Aegon VII]

On August 31, 2017 at 7:25 AM, Hangover of the Morning said:

How does a second son from a relatively minor, albeit famous, far-away house become best friend with the crown prince? We can only speculate as there's very little to go on in the canon. We only know that Arthur was Rhaegar dearest as well as oldest friend. To me that implies that they have known each other from childhood or early teens.

My guess is that the boys have squired together for the same lord (Jaime and Merrett Frey or Tywin/Aerys/Steffon scenario). Alternatively, Arhtur could have been "fostered" in King's Landing for a period of time. Rhaegar grew up as an only child (Viserys was born when he was 16) and it's not unusual to bring other noble children to the court to keep the prince company. 

How do you think that those two met?

When your the best you surround yourself with the best