Win or lose, you will answer for it. That's what Kings do.
Henry to Francis about the role of being King
In the Pilot, King Henry prepares to join Catherine in celebrating the wedding of their daughter Elisabeth when Francis pops up and Henry tells him that his wedding won't happen until he says so. Henry is also seen making out with Kenna for the first time.
In Snakes in the Garden, Catherine and Henry are discussing Charles’, Francis’ younger brother, future wedding to Madeleine, who is French as well so they would not have to worry about her loyalties. Later, Henry questions Catherine on why she did not inform him when she found out Colin was still alive, and that he should be notified of these things immediately, regardless if he is with his mistress or not, day or night. Henry seems mistrustful of Catherine, and her interactions with Nostradamus.
Francis is showing something other than disdain for Mary in his father’s presence for the first time, brings his concerns about the English to Henry’s attention. Henry doesn’t care, is intent to keep Mary in France to use as a weapon when he sees fit. After Francis mentions ending the engagement and sending her back to Scotland, he learns that Mary’s mother does not want her back without a king as a husband and an army to potentially use. Henry calls Francis out on his intentions, questioning his worry about someone he doesn’t want to marry.
Henry visits Kenna’s rooms with the man she was with earlier. He asks if he would be willing to marry Kenna, no questions asked, if he had the blessing of his king. When he agrees, and is sent on his way, Henry informs Kenna that her prospects expands when she is in the King’s favor. He then pulls her into a kiss and tells her to think about his offer.
In Kissed, when hearing of England making its move on Scotland’s border, Mary demands that King Henry send companies to Scotland’s defense. The King however has no intention of actually helping out, since the potential loss of those companies could send a message to France’s enemies that they’re weak.
At the ball, Nostradamus warns Catherine that the vision means that the cost of war will soon find its way inside the castle walls, and this terrifies the Queen. However, Henry isn't nearly as convinced of the seer’s power, and so he forces him to tell the fortunes of Mary and her ladies-in-waiting.
King Henry continues to rebuff his sexual advances towards Kenna but she begs for more time to consider. Later, Henry and Francis have a sparring duel and wager toward the outcome: if Henry wins, Francis will stop bothering him about helping Mary; if Francis wins, Henry will provide military support to Scotland. Francis wins, yet Henry refuses to honor his word, saying that it’s the job of a king to make many promises. Francis learns that Henry has been messing around with Kenna and essentially blackmails him into helping Scotland by threatening to reveal the affair to both Catherine and Diane. Surprisingly, instead of being furious with his son, Henry overjoyed that Francis is showing the sort of cutthroat attitude he feels a King should have, and so he agrees to have Francis send the fastest ride in the realm to signal the ships to set sail for Scotland. The fastest rider is Bash and the decision to send him on the errand places him directly in harm’s way, since they’re all unaware that English forces are already present. The next day, Bash returns wounded, having been the person in Nostradamus’ vision. His life hanging in the balance, Bash reveals that by the time he got to the ships, the English were already on the attack, obliterating their forces. Francis begs his forgiveness for putting him in danger, an act that sends Henry into a furor, saying that a king never apologizes. He tells Francis that he can’t ever hope to rule with his emotions, and it’s a lesson Francis takes to heart.
In Hearts and Minds, Henry re enters negotiations for the wedding of Mary and Francis after she, Francis and Bash save Simon the English Envoy from being executed.
In A Chill in the Air, Henry does not appear in this episode but has asked Kenna to become his official mistress. He is in Paris, going to see Diane.
In Chosen, Henry and Kenna get into a small spat over Diane coming back to court and why he won't change the tiles. Later, Henry still ends up in Diane's bed that night.
In Left Behind, he is dealing with a peasant uprising, thus leaving him absent.
In Fated, he announces his plan to have Mary and Francis married, so that Mary would also take her claim on the English throne, as the English Queen is on her deathbed.
In For King and Country, as the guards caught Mary and Sebastian, he threatens to kill Bash if Mary doesn't take her claim on the English throne. As Mary decides to take her claim only if she marries Bash, Henry is forced to legitimize him. He says he shall leave for Rome.
In Sacrifice, he is in Rome trying to negotiate Sebastian's legitimization. The legitimization plan fails and Mary is tricked into rushing in marriage to Francis.
In Inquisition, Henry accuses Queen Catherine of adultery, and they get into a heated discussion about their marriage which reveals that Henry had a huge role in the breakdown of their marriage. The Royal couple eventually melt into each other's arms again, and make love which leaves Henry with doubts about killing his wife; however when he discovers that Catherine had an affair with his friend Richard and had a child. Catherine is convicted of adultery and sent to the tower to await her death.
In The Consummation, Henry pardons Catherine for the wedding of their son, Francis, and Mary.
In Dirty Laundry, King Henry accidentally causes the death of Archduchess Cecelia sister of the visiting Archduke Ferdinand of Bohemia, and asks his Queen of all people to help him cover up her death as there is no one at court who is better at this than his wife. This seems to bring them closer together and he tries to kiss her but she backs away from him.
In The Darkness, King Henry is showing early signs of being ill, Kenna finds a woman dead in Henry's chambers and asks Catherine to help her as she is scared for her life. Catherine tries to help Henry as she is becoming worried about him, but he rejects her help telling her that this will remain a secret between them.
In Monsters, Henry's illness becomes more obvious after a servant named Penelope wins "Queen of the Bean" and Henry becomes obsessed with her. Henry and Penelope poison Catherine after she tells Henry that Catherine threatened to kill her if she didn't kill Henry first.
In Liege Lord, Henry is showing further signs of illness so much so that Catherine is having all important matters diverted to her so that she can look after France without alerting the country to her husband's illness.
In No Exit, Henry finally gets rid of Penelope after a visiting Bishop condemns his behavior, and Henry collapses in his Queen's arms and realizes that he is going to need her if he is going to survive.
In Toy Soldiers, Henry's illness is reaching an all time high, as he caters to his mistress, Penelope, who pretends to be pregnant with his child in order to attempt to get back in his good graces.
In Long Live The King, Henry is becoming increasingly irrational as he is inspired by Francis leading the successful taking of Calais to immediately seize the throne of England now that Mary Tudor is dead. Francis tries to delay his father leading to Henry's feeling that his son is unsuited for conquest so he must kill his son, marry his daughter-in-law, Mary, and take England with her by her side.
In Slaughter of Innocence, Henry is becoming more mad by the minute leading to Catherine, Francis, and Mary to plan a coup. At the Joust to celebrate the victory at Calais, Mary arrives wearing the English Seal. He is impressed by her decision and is inspired to take a turn at the celebratory joust himself, but Henry's opponent is Francis who changed places with the original jouster. Francis mortally wounds Henry by putting his lance through the face shield. On his deathbed, Henry makes his Queen promise to befriend Diane, and they confess their true love for each other as the loves of their lives. Then Henry confesses to Francis that he poisoned his younger brother and warns him not to betray those he loves. Henry then dies leaving Francis as the new King of France and Catherine as the Dowager Queen Consort of France.