[Once he confirms that she's listening--well, his own pause first makes him think of Old Nan, and a flash of sadness passes through him at that. But now is not a time for sad thoughts: now is a time for knights, and so he pushes that feeling down.]

Targaryens always wed brother to sister--they were of Valyria, so they kept that custom even after they conquered Westeros and took up rule there. Aemon loved Naerys, but theirs was a doomed love. [Love stories are good when it's doomed love, and Bran takes a moment to enjoy that.] Aemon was only the second son, so it was his elder brother, Aegon, that married Naerys.

Aegon was unjust and unfeeling, and there was no honor in him. And Naerys was very beautiful, and had no love for Aegon--but Aemon served his brother nobly, and did not interfere with the marriage--though he must have wanted to. He wept at their wedding, but he never spoke against his brother and defended him well.

With Naerys as queen, he could defend her, too--and he did. When the knight Ser Morgil called her unfaithful and slandered her name, Aemon rode to defend his sister's honor. It was foolish of Ser Morgil to meet him on the field, for there was no blade in all of the Seven Kingdoms that could have stood against Dark Sister. [Another pause, and he adds, thoughtfully:] Perhaps Ice could have stood against Dark Sister.