Henry V - the lion - is dead.
Henry VI - the lamb - accedes the throne after years of regency.
Unlike ConnIggulden's series on Genghis Khan and his book Dunstan - Stormbird (War of the Roses 1) does not start of with the childhood of the main character, so this isn't a coming of age story. The other difference between the books is that there is no one main character in Stormbird, there are multiple points of view over this struggle for the throne of England starting in the mid fifteenth century. This conflict was named the war of the roses over the white and red roses which symbolized the opposing factions - the Yorks and Lancasters. If it sounds similar to George RR Martin's A Song of Ice and Fire series that's because the historical war of the roses and medieval English history made up some of the source material / inspiration for ASOIAF. The major difference obviously is that George RR Martin's series is fantasy and Conn Iggulden's War of the Roses series is historical fiction, and therefore more grounded. Both are thick in scheming, and recommended if you enjoy political intrigue.
The prologue (set in 1377 AD) foreshadows the premise with the death of the Plantagenet king Edward III surrounded by some of his sons, but these aren't the players squabbling over the throne - those comes a few generations later. Also quickly established in chapter one (1443 AD) is the weakness of the contemporary king - Henry VI (Henry the lamb) son of Henry V (Henry the lion). The lamb has no stomach for battle and urges his spymaster -Derihew Brewer - to sue for peace. Brewer takes William de la Pole into confidence, and moves to end the constant battling with the French by marrying the king to respected, old (bankrupt) French nobility. Brewer impresses the need to move fast - before the French realize they are up against a weak king, and he reminds William that the best they can hope for is a strong son - and he recalls kings of old.
The future queen Margaret of Anjou is the daughter of Rene, Duke of Anjou who calls himself the king of Jerusalem, Naples and Sicily but his home of Anjou is held by the English, and he is in deep debt. Rene quickly takes the blessing of king Charles of France who in turn agrees to secure the blessings of the Pope for an incestuous marriage (Henry VI is his nephew and Margaret his niece). The Duke of Anjou also engineers the hanging of his creditor - a Jewish trader and moneylender with the assistance of rampant antisemitism of the time.
The machinations of the English courtiers go as planned but the aftermath of the marriage and the terms of surrender of English lands (Anjou and Maine territories - combined they are as large an area as Wales) on the continent (in modern French territory) give rise to chaos and unrest among the continental English subjects. Richard - the Duke of York and commander of the kings forces in Normandy who resides on English land in Europe is unable to plead his case before Henry VI, and is sent to Ireland. Richard holds Brewer and William Pole responsible for the loss of land in France, and doesn't remain idle.
In France there are thousands of other subjects who have to leave with what belongings they can carry on their backs and have no livelihood in England. While some leave a few refuse and put up a fight on the advancing French forces who are marching to take land and property left behind, and are not above the crimes of war. Leading this rebellion is Thomas Woodchurch - farmer, formerly an archer in the English army.
The description of battle illustrate military tactics of the time and how the superior numbers of the French were no match for the archers of the English army for several past and current battles. Nor were the French quick to learn the newer technology - thinking the archers cowards for fighting from a distance. The French nobility preferred the use of swords and close combat, placing the means of battle over the ends and suffering for it. Richard of York, before leaving for Ireland, pulls the English forces back to Normandy (English territory) and declines to provide cover to the withdrawing English subjects or help the resistance. The spymaster Derihew Brewer, his acolyte William de la Pole and by default Henry VI have become Richard's adversaries and he is has no intention to mitigate the situation for their favor; in fact he is counting on the blame for the chaos and discontent to fall squarely on Brewer and Pole in the aftermath.
This fallout of Henry's marriage to Margaret brings to the fore the crown's other troubles. The king's unwillingness and possible inability to fight had long been the topic of discussion among earls, dukes and his other subjects. Richard of York backed by his powerful in-laws - the Nevilles, moves quickly to further undermine the crown. He gets William Pole exiled for treason, and himself appointed heir to the throne in case the royal couple do not produce a child.
Meanwhile it is not just the court that is conspiring to bring down the king, even the common people are rallying around one Jack Cade, who's leading a rebellion and marching on London.
The use of force and its repercussions are a major theme in Strombird. The place of women to be used as political pawn in marriage is shown through Margaret's marriage to Henry; her subsequent metamorphosis to take a more active role in court as her husband recedes further into the background was not expected. The surrender of the English lands of Maine and Anjou without consultation or notice to the subjects who lived there was met with a rebellion; this in turn provoked the French army and the resulting battles led to unrest in the king's court. And finally the capital punishment meted out to Jack Cade's son for a minor crime is described as the nucleus of the rebellion that shook London. Another minor example is the engineered capital punishment of Reuben Moselle - Jewish moneylender and creditor of the Duke of Anjou who is killed with impunity in an atmosphere of rampant antisemitism.
Parallels can also be drawn between other elements from Game of Thrones - Robert Baratheon's friendship with Ned Stark is mirrored in Derihew Brewer and William de la Pole, who have two very different personalities. William de la Pole is a warrior who moves cautiously, is not necessarily comfortable with change and prioritizes honor. Brewer is a manipulator who thinks several steps ahead was somehow blindsided by the fallout of English territory and yet remains powerful. William is part of the aristocracy and an Earl by rank, he remains skeptical of plans in light of his experience on the battlefield. Brewer, also experienced in battle, is a self made man and moves and speaks with unshakable confidence. Another parallel is the rebel leader Jack Cade - an uneducated man who does not fully grasp the potential of his following, and Thomas Woodchurch - who joins the rebellion and advises the unlettered and aggressive Cade, not unlike how a younger Ned Stark is assumed to have helped Robert Baratheon - the popular face of against the Mad King Arys.
Other comparisons can be drawn between the royal couple - Margaret, who was a pawn in political games but shows promise of intelligence and will, and her husband Henry who is taken in by religion at the cost of his duty. Contrast them with Tommen of the House Baratheon and Queen Margery.
York versus Lancaster
Political intrigue & plots
Weak king, powerful courtiers