The Second Sons are a mercenary company found in the Free Cities. At Yunkai, where they were contracted to face Daenerys Targaryen and her forces, they numbered five hundred men. Their banner is a broken sword.
Their camp is a circle of ragged tents. There is a cook tent. Brown Ben Plumm’s tent has painted canvas walls cracked and faded by years of sun and rain, within the tent are camp stools and a tresel table, a rack of spears and halberds and a floor covered with threadbare carpets in half a dozen clashing colours.
The Second Sons are amongst the oldest of the free companies. They do not enjoy the shining reputation of the Golden Company, but they have won some famous victories.
They once fought alongside the Three Thousand of Qohor and the Bright Banners outside the gates of Qohor. Under the command of Mero, their reputation has fallen to the point where it has become hard for them to find work in the Free Cities.
The names of every man to serve with them is written in a book, when they joined, where they fought, how long they served, the manner of their deaths. The Second Sons are on their fourth book. The book is leather bound with iron hinges, and large enough to eat your supper off. Inside the heavy wooden boards are names and dates going back more than a century.
A tradition of the company is so sign in red ink. There was a time when each new man wrote his name in his own blood, but that tradition faded as blood makes poor ink. Tyrion chooses to sign in the traditional way: in blood. He signs his name in a big bold hand: Tyrion of House Lannister, Lord of Casterly Rock, just below Jorah Mormont’s far more modest signature.  Afterwards Inkpots dusts the page with fine sand.
There are famous names in the books: some from the Seven Kingdoms. Aegor Rivers served a year with them, before he left to found the Golden Company. The Bright Prince, Aerion Targaryen and Rodrik Stark, the Wandering Wolf also served. At present, with the addition of Tyrion and Jorah Mormont, they number five hundred and fourteen members.
The Second Sons armourer is Hammer; his apprentice is Nail. The Second Sons keep their company armour in six big wayns drawn up near the center of their camp. Under roofs of bent wood and stiffend leather, the wagon beds are heaped high with old weaponry and armour. Most of the iron is not very good; it is not just old and ill-fitting but dinted, cracked and brittle with dried blood or rust. According to Ser Jorah Mormont there is some sound steel in there, none of it is pretty, but it will stop a sword.. Some of the armour in the wayns are what sellswords were wearing when they died and some of it is made to fit boys.
Ser Jorah Mormont clads himself from head to heel in company steel. His greaves are mismatching, his gorget is spotted with rust, his vambraces rich and ornate, inlaid with niello flowers. On his right hand is a gauntlet of lobstered steel, on his left a fingerless mitt of rusted mail. The nipples on his muscled breastplate have a pair of iron rings through them. His greathelm sports a ram’s horns, one of which is broken.
Upon entering one of the wayns Tyrion and Penny find a rusted iron half-helm and then a greathelm, a crossbow, a Morningstar, a warhammer, a studded mace, and half a dozen longswords. Tyrion finds a dirk he likes - a nasty piece of steel with a triangular blade with a bit of rust on it. He finds a wood and leather sheath that fits and slips the dirk inside. He remarks that the longsword Penny picks up is notched, denoting that it is cheap steel. He examines a heavy shirt of iron mail so full of holes it almost looks moth eaten. The Second Sons company steel is worse than what he fought in at the Battle of the Green Fork.
- Mero, better known as the Titan's Bastard
- Brown Ben Plumm, captain and commander
- Kasporio, the Cunning, second in command
- Tybero Istarion, better known as Inkpots, paymaster
- Hammer, blacksmith and armorer
- Nail, apprentice to Hammer
- Snatch, serjeant
- Uhlan, serjeant
- Kem, young sellsword
- Bokkoko, axeman
- Ser Jorah Mormont, sellsword
- Tyrion Lannister, assistant to Inkpots, (Penny: attached to Tyrion, she does not sign the Second Sons book)
A Storm of Swords
The Second Sons were employed by Yunkai to defend them against the threat of Daenerys Targaryen. They were placed on the left of the defensive line that faced Daenerys's army. they were commanded by Mero, known as the Titan's Bastard. Mero attended the parley with Daenerys and decided to mull her offer of switching sides or departing only on the condition that she give him a wagon of wine. He brought the wine back to his men and while they were getting drunk on it that night, Daenerys sent her forces on the attack. The Second Sons were routed and Mero fled before he could be captured.
A Dance with Dragons
Daenerys sent them south to guard Meereen against any incursions by Yunkai. However when Brown Ben Plumm learns that Daenerys cannot control her dragons anymore and use them against the Yunkai, he has his company go over to the Yunkai.