Jaehaerys and Vermithor (Patreon)

"He grows larger every day," Jaehaerys said as he scratched the great wyrm under his jaw. "Keep your nieces and your nephews, my lord. Why would I need hostages? I have your word, that is all I require." But Grand Maester Benifer heard the words he did not speak. "Every man and maid and child in the stormlands is my hostage, whilst I ride him, His Grace said without saying," wrote Benifer, "and Lord Rogar heard him plain. "

Or "Speak softly and carry a big stick/dragon"--Jaehaerys I Targaryen, probably.