|Book(s)||A Dance with Dragons (appears)|
Marq has a pox-scarred face that has a hole in one cheek where a slaver’s mark had been burned away. He wears his worldly wealth upon his person, including a lord’s ransom in golden arm rings and a chain of golden skulls. Each arm ring signifies one year's service with the Golden Company.
Marq is a Westerosi exile that escaped from slavery at some point. How he came to be enslaved, where he was a slave and for how long is not known. His surname Mandrake is of a house that once loomed large in the histories of the Seven Kingdoms. He may or may not be of House Mandrake, as in the free companies a man can call himself whatever he chooses.
A Dance with Dragons
During his rendezvous with the Golden Company three miles south of Volon Therys, Jon Connington reveals that Young Griff is in fact Prince Aegon Targaryen. Silence greets his announcement. He notices Marq Mandrake and Jon Lothston exchange a glance, and Jon Connington realizes they have already known. Marq, like the rest of the company, swears his allegiance to Aegon before they invade Westeros.
In Westeros, during Jon Connington and the Golden Company’s war council at Griffin's Roost, it is disclosed that Marq was put ashore by the Volantenes on what turns out to be Estermont with close to five hundred men, although the island was never one of their objectives. He leads his troops and takes Greenstone.
Connington figures there should be ships on Estermont as it is an island. He instructs Haldon to send word to Marq to leave a garrison behind and bring the rest of his men to Cape Wrath, along with any noble captives.
—Laswell Peake and Marq