As seen in the House of the Dragon, a war of succession broke out between siblings, Rhaenyra Targaryen and Aegon Targaryen (not the original one), and the result was known as the Dance of the Dragons.

Aemond Targaryen is probably my favourite character in the House Of The Dragon storyline. An almost perfect opposite of Daemon he's one of the most cunning people in all of Westeros.

The original Rhaenyra and Alicent actors, Emily Carey and Milly Alcock, were replaced in House of the Dragon by Olivia Cooke and Emma D’Arcy.