Were there ever any reasons given as to why Robert and Ned were fostered?

[Bastard of Balmora]

This is something I probably overlooked when I read the series, on my current re-read I'm asking myself constantly: Why were Ned and Robert fostered? Was this just a normal thing or was there some sort of problem that sent them to the Eyrie?

I ask because the term foster makes me think differently from being sent to squire or learn how to conduct themselves proper.

[The hairy bear]

In most cases it seems that there's always a reason for sending a boy away: a punishment for their fathers (Theon is fostered by Ned Stark after his the Greyjoy's rebellion, and Quentyn was sent to the Yronwoods after the Red Viper poisoned Lord Ormond in a duel), they are orphans without a fatherly figure to educate them (Robert Arryn planned to being sent to Dragonstone or Casterly Rock), or bastards that their father's wives should not have to bear in their presence (Edric Storm at Strom's End, Larence Snow at Deepwood Moote).

But in ADWD we learned that Brandon Stark was fostered at Barrowton, and Jaime Lannister was Lord Crakehall's squire since he was eleven. I would say that fostering youg boys is common among noble families.

[The guy from the Vale]

This is something I probably overlooked when I read the series, on my current re-read I'm asking myself constantly: Why were Ned and Robert fostered? Was this just a normal thing or was there some sort of problem that sent them to the Eyrie?

I ask because the term foster makes me think differently from being sent to squire or learn how to conduct themselves proper.

Fostering is used among noble families to strengthen bonds between these families. It can also be a punishment and reassurance for the winner of a war, as in the case of Theon Greyjoy.

In Ned's case, it was probably a case of strengthening an alliance; while we learn in ACoK that Robert was fostered mainly because his parents had died in a storm. We don't know if Robert was sent to the Eyrie before they died or after, though.

[Rolex Baratheon]

I was just about to ask the same question. Was Ned's family fully stable? And who was Ned's mother? We do know that Robert's parents died in that Shipbreaker Bay incident.

[weaselontherun]

Eddard was a second son therefore under normal circumstance not entitled to the wealth his older brother would inherit. Fostering to a Lord such as Arryn would put Eddard contact to larger array of major & minor houses. These may have unmarried daughters and might require a champion from a leige house for alliance purposes..

We know nothing of Ned's mother at least from my read.

[The hairy bear]

we learn in ACoK that Robert was fostered mainly because his parents had died in a storm. We don't know if Robert was sent to the Eyrie before they died or after, though.

We do know that Robert's parents died in that Shipbreaker Bay incident.

Robert's parents died on 278, when Robert was 16 years old. It makes little sense that he was sent to the Eyre then, because according to Westerosi standards at this age he would already be a grown man ready to rule as Lord of the Stormlands.

And Eddard (who has the same age as Robert) says that he was sent to the Eyrie when he was eight.