The bells of King's Landing

Having lost her friends, her dragons and most of her reasons, Daenerys takes the city after it has already surrendered and burns it anyway. Whether this is a betrayal of the character or the destination she was always walking toward is the argument the fandom has been having ever since.

The fuller tale

By the time the fleet reached King's Landing, Daenerys Targaryen had lost most of what she had brought and most of what had kept her steady: two of her three dragons, her closest friend executed on the walls in front of her, her oldest adviser, her fleet ambushed, and a realm that had made it very clear it was not going to love her the way Essos had.

The city was taken quickly. The Golden Company's gate went in with the first pass; the Lannister forces in the streets threw down their swords; the bells rang from the towers, which is the signal for surrender and is understood by every soldier in Westeros.

Then she burned it anyway. Street by street, for hours, on a city that had already given up ÔÇö the Unsullied and the northmen following her lead into the smoke, and Jaime and Cersei Lannister ending under the Red Keep, and a number of the dead that nobody has ever seriously tried to count.

The argument that has not stopped

Whether this is the destination the character was always walking toward or a betrayal of her is the longest-running argument the story has produced, and both sides have real evidence. Her family's history is full of people who burned what would not yield; she had crucified, burned and executed before, always with a justification; and she had been told for years that fear was the only thing that had ever worked for her.

Against that: everything she had ever done was for people who had nothing, and she incinerated a city full of them. The chronicle records what happened and declines to settle it.

Elsewhere in the wiki

 See the world as it stood in 305 AC 

What became of it ÔÇö if an ending is written, it is here. Spoilers.

The chronicle records no ending here ÔÇö or none the maesters have set down.