why were elia and her children left defenseless?

[Lord Warwick]

this is a real anamoly. Aerys shipped off his pregnant wife and son. Who were 2nd and 4th in line for the throne.

but he took no steps to defend aegon, who was the heir to the iron throne?

was he aware of the baby switch but then what about rhaenys?

now we know aerys was mad. Did he give precedence to his own children over his son's children? Was this some sort of delusional pride?

Jaime was left to defend the king but why no kingsguard for the future queen and king.

Rhaegar took lewyn martell to the trident because he was a dornish prince and could command the 10k dornish troops.

He took barristan because of his great experience in war but couldn't he leave jonathon darry to protect his wife and kids?

surely he was no damsel in distress who needed an additional knight to defend him. And why put three living legends in dorne to guard lyanna, why not just arthur dayne and oswell whent? wasn't the lord commander supposed to do some important duty like defending the capital or leading the army in battle?

[Game Of Thrones]

Aerys thought Dorne would betray him and kept Elia a hostage.

[Cold Crashing Waves]

She was protected until the Mountain killed her protectors.

[Hos the Hostage]

There is no indication that they were unguarded. A large Lannister host sacked KL. One knight or two would not have made a difference. The situation at ToJ was different.

[joluoto2]

1) because Rhaegar left three KG members at the Tower of Joy.

(why he needed three KG members there is still a mystery, since one would probably be sufficient.)

2) because Aerys held Elia and her children hostage to force Dorne to back him (otherwise I suspect they would have fled to Dorne when the war broke out).

[Loge]

Aerys had grown paranoid and didn't really trust anybody anymore, including the Kingsguard. He kept Jaime as a hostage as much as a guard. Elia also was a hostage. After the Trident Aerys went completely nuts and tried to burn down all of King's Landing. Not exactly a star of mind where you think about the line of succession.

[Tyrus Martell]

We didn't hear the full story from those that were present during the Sack of King's Landing. Most accounts throughout the five books from P.O.V.s (Kevan Lannister, Jaime Lannister) or characters who were known to be there (Tywin Lannister, Thoros of Myr) glossed over what exactly Gregor Clegane and Amory Lorch had to do to get to Elia and her two children after scaling the Red Keep.

If we consider what we do hear about the Sack, the situation within the city seemed pretty hopeless, so I wouldn't be surprised if the remaining City Watch and personal guard of the royal family fled from the Red Keep or were already killed.

Tyrion Lannister also tells Oberyn Martell he recalls hearing of other House Lannister guards present during the murders of Rhaenys and "Aegon" (I added this to the ASOIAF wiki as I think this fact is fairly overlooked), which means Amory and Gregor had help if there were indeed some unmentioned guards protecting Elia and her children.

[PirateVergo]

Because Rhaegar was a fool or did not care for her otherwise he would have sent her and the childrens at Dragonstone;

[Capt Captain]

There would have been some house-hold guards and the sort, but you should remember that it wasn't only Clegane and Lorch attacking to get them. Also, the guards were probably in other defensive positions to hold out as long as they could, but the might not have seen Gregor and Amory scaling the walls.

[Ramsay Gimp]

They surely had guards, Gregor just cut through them. He is the Mountain, after all. He and Lorch had a number of men-at-arms with them as well

[joluoto2]

They surely had guards, Gregor just cut through them. He is the Mountain, after all. He and Lorch had a number of men-at-arms with them as well

Tbh, while not saying Rhaegar wasn't a fool, I don't think he could do that, since Aerys had decided to use them as hostages to force the Dornish to cooperate.

[Fire Eater]

Because Rhaegar was a fool or did not care for her otherwise he would have sent her and the childrens at Dragonstone;

Except that wasn't Rhaegar's decison but Aerys as has been clearly mentioned.

There was a force of a few thousand in KL, and Targaryen men in the RK.

He left three KG with Lyanna, because he feared for life after Aerys killed her father and brother, and demanded the heads of another brother and her betrothed.

Rhaegar was dealing with the threat by putting himself and his army between Robert and KL.

[assjfjgjsgjljljglgjfjsduar]

Because Rhaegar was a fool or did not care for her otherwise he would have sent her and the childrens at Dragonstone;

It wasn't Rhaegar's call to make, it was Aerys's. Aerys wanted them to stay in the capital (which would have been fortified and filled with many other guards and soldiers besides the Kingsguard) in order to ensure that the Dornish stayed loyal. We don't know what Rhaegar would have done with them if he had had a say.

[RoamingRonin]

now we know aerys was mad. Did he give precedence to his own children over his son's children? Was this some sort of delusional pride?

Yes!

ETA: In a way, Elia and her children were just as safe as Aerys was, minus the kingsguard and whatnot. But yes! Aerys thought to protect his children while he and Rhaegar's children remained where the imminent danger was.

[Queen Ayras Lord Commander]

1) because Rhaegar left three KG members at the Tower of Joy.

(why he needed three KG members there is still a mystery, since one would probably be sufficient.)

2) because Aerys held Elia and her children hostage to force Dorne to back him (otherwise I suspect they would have fled to Dorne when the war broke out).

Because it symbolically implies that Rhaegar valued what was in the ToJ over his known family. I won't proceed further with spoilers.

We didn't hear the full story from those that were present during the Sack of King's Landing. Most accounts throughout the five books from P.O.V.s (Kevan Lannister, Jaime Lannister) or characters who were known to be there (Tywin Lannister, Thoros of Myr) glossed over what exactly Gregor Clegane and Amory Lorch had to do to get to Elia and her two children after scaling the Red Keep.

If we consider what we do hear about the Sack, the situation within the city seemed pretty hopeless, so I wouldn't be surprised if the remaining City Watch and personal guard of the royal family fled from the Red Keep or were already killed.

Tyrion Lannister also tells Oberyn Martell he recalls hearing of other House Lannister guards present during the murders of Rhaenys and "Aegon" (I added this to the ASOIAF wiki as I think this fact is fairly overlooked), which means Amory and Gregor had help if there were indeed some unmentioned guards protecting Elia and her children.

Jamie has a dream which indicates Rhaegar thought he'd protect his family, at the very least.

Also, Elia and co. were in MK, which is a fortress within a fortress. They were guarded, just not well enough.

[The Kinkslayer]

Because out of Aerys, Rhaegar and Viserys, Viserys was the clever one

[Dany Girl]

They were guarded, they were arguably in the safest place they could be. The Red Keep would have been filled with Gold Cloaks, as well as the walls of the city. But once Tywin was allowed into the city with his host, the GCs were preoccupied. Tywin was allowed in under false pretenses. If Aerys listened to Varys over Pycelle, Tywin never would have been allowed in and Elia and her kids would be fine.

As it was, the GCs found themselves fighting Lannister troupes outside the RK, or even inside. No one probably thought Elia was in danger because the enemy host didn't pass them, or once they did, the GCs were dead. Amory and Gregor scaled the walls, meaning they bypassed the guards. Even if the guards cut down every Lannister troupe, they could not forsee the assailants scaling the walls. Elia and the kids might have had guards inside their rooms, but they'd be little match for Gregor and Amory.

Aerys of course thought keeping Elia and her children in KL would secure Dorne, which it did. But he didn't foresee Tywin coming to him under the flag of truce only to attack once in the city. Aerys actually made the best call he could have made for his strategic side, he just over estimated Tywin's loyalty to him.

[Queen Ayras Lord Commander]

The Gold Cloaks have been unreliable at several points in the past.

[Aetta]

Elia should be no more safe than the king of the freaking continent. The king wasn't safe, do the math.

[Aetta]

Awful attempt at editing my previous post. Yes, the king should have been safe, but he wasn't in the end. So it stands to reason that no one below his status would be, either, save Jamie, since his daddy was the one doing the sacking.