This is basically when someone could not have otherwise become king without their mother's efforts. It doesn't have to necessarily be a king—it can refer to any situation where your mother makes sure you have power.
It could be that your mother is a political actor in her own right who plans to get you into power, scheming and murdering all other heirs and finally you become king. A woman in such a society can't be head of state, so her son becoming king is the next best thing. In that case, she's likely the Woman Behind the Man, and her son, once he's in power, may be a Puppet King.
For gender reasons (Heir Club for Men), daughter variants are less common, but not unheard of—many an ambitious mother paraded her beautiful young daughter before a king in hope she'd be picked as a Hot Consort. In that case, it sometimes becomes a three-generational plan: She gets her daughter made queen, and then her daughter has a son who will become king.
Merely inheriting your throne via your mother's line doesn't count; your mother has to actively support you in assuming the position. (This usually means scheming.)
While it doesn't actually have to be becoming king, that is the most common case. Historically, a king's father usually had to die before he could become king, but many kings' mothers were still alive and well during their reigns, often titled "Queen Mother." In the Ottoman Empire, sultans tended to have royal harems with many concubines—but they only had one mother. She was effectively their queen, the second most powerful person in the empire after the sultan himself, and bore the title "Valide sultan."
The mothers in question tend to be villainous, often overlapping with Evil Matriarch and God Save Us from the Queen!. This is doubly true if the son in question is secretly illegitimate, or otherwise not the biological son of the late king, making him not the "rightful heir". If her son has half-brothers in line to the throne before him, she will certainly be a Wicked Stepmother to those stepsons.
Subtrope to Vicariously Ambitious. The mom in question is (whether heroic, villainous, or any combination thereof) most likely an Almighty Mom. If she was married to a king, she may have been a Lady Macbeth as well.
- Anatolia Story: Queen Nakia's goal is to invoke the trope with her son Juda no matter what, and is trying to kill her stepsons.
- In Fushigi Yuugi, Hotohori's mother pulled some strings to get him onto the throne. Conveniently, the real crown-prince, Tendou, had been sent away to live as a commoner, because someone made an attempt on his life.
- In Kaiba, Warp's mother poisoned him, giving him just enough poison to make him indisposed during the war of succession, in which all his brothers died.
- Zira from The Lion King II Simbas Pride will do anything to make her son Kovu king.
- In Shrek 2 Fairy Godmother tries to put her son Prince Charming on the throne by marrying Fiona, an only child and heir to The Good Kingdom; the original plan was for him to have saved Fiona from the dragon's tower, but he got there after Shrek had already saved her and married her. So Fairy Godmother tries to get rid of Shrek other ways, setting up the whole plot of the movie.
- Chronicles of the Kencyrath:
- Kenan, Lord Randir, owes his position entirely to his mother Rawneth's efforts, including driving the rightful heir into exile. Bonus points because Kenan's secretly illegitimate. Rawneth's strongly implied to be the power behind the throne, as it's said that mother and son speak with a single voice, and the one action Kenan takes without his mother's input is a failure.
- Timmon's mother Distan is strongly implied to be this. Lord Ardeth—Distan's father—is very old and will die in the foreseeable future, and she wants her son to be the next Lord Ardeth.
- In Kothifir, Princess Amantine is this to her son Ton. With his support he makes an attempt to usurp the throne, though he fails.
Amantine: Face the truth, boy. Where would you be without me? Even if the white should truly come to you, you need my guidance
- In The Crown Jewels by Walter Jon Williams, we learn that this is how the current Khosali Emperor, Nnis CVI, got his crown. The eldest does not automatically inherit—the current Emperor chooses his heir from the children of his harem. Nnis, though a son of the emperor, had absolutely no interest in his father's throne. His goal in life was to publish scholarly papers on insect genitalia. Unfortunately for him, while he was off on a remote planet studying crawling things, the designated heir died, and Nnis' mother managed to get Nnis chosen as the new heir. Nnis went rushing back to try to start a counterconspiracy aimed at getting himself removed, but before he arrived at the capital, the Emperor died, and he was stuck.
- Godspeaker Trilogy: The first book is about a nameless brat who rises to Mother of the Heir via slavery and soldiery with divine guidance. Her ambition is to use her son as a "Hammer" to take over the world.
- How to Train Your Dragon: Excellinor the Witch, mother of Alvin the Treacherous, is able to make her son King of the Wilderwest through her scheming.
- I, Claudius claims Livia Drusilla was this to Tiberius.
- Kushiel's Legacy: Lyonette de Trevalion, known as "the Lioness of Azzalle," is a Princess of the Blood, and plots with her son Baudoin to get him on the throne. It becomes a Defied Trope when both mother and son get caught, put on trial, and executed for treason.
- The Riftwar Cycle has a protagonist example: At the end of Mistress of the Empire, Mara of the Acoma puts her son Justin on the throne by marrying him to the daughter of the late Emperor, making him the next Emperor.
- A Song of Ice and Fire loves this trope.
- Queen Cersei Lannister puts her secretly illegitimate son Joffrey in line for the Iron Throne by passing him off as King Robert's legitimate son. She then gets him on the throne by killing Robert and his bastards (whose physical appearance would proved that Joffrey wasn't Robert's), and having a person who discovered her secret imprisoned on charges of treason. Because he's young, she—in varying degrees—rules in his name, thought he's a loose cannon and sometimes goes off on his own.
- Rather interestingly, in a gender-inversion, Cersei herself became queen thanks to her father Tywin's scheming. It took two tries—the first prince he tried to marry her to said no—but he got it in the end.
- Visenya Targaryen—one of Aegon the Conqueror's sister-wives—is suspected of this, with her stepson/nephew King Aenys I dying from an illness while under her care. Her son Maegor the Cruel then became king and she became his strongest supporter. Then deconstructed, as after her death Maegor's reign begins to fall apart and he is overthrown by one of Aenys' sons.
- Queen Alicent Hightower was apparently this. Her husband Viserys I had declared his daughter Rhaenyra—the only surviving child of his first marriage—his heir. Alicent persuaded her oldest son Aegon II to take the Iron Throne, leading to a civil war known as "The Dance of the Dragons." By the end, Aegon II died. Of course, it is disputed how much of Aegon's actions were due to Alicent, considering Archmaester Glydan shows some misogynistic views.
- During the chaos that engulfed King's Landing during the above-mentioned Dance of the Dragons, a woman named Essie claimed that her son Gaemon—four years old at the time—was the bastard of Aegon II and proclaimed him king. After the city was reclaimed, she was hanged.
- Dark Matter: Empress Ishida is scheming to make her son Hiro the emperor. This is not good news for her stepson Ryo, who stands between Hiro and the throne.
- Game of Thrones: Like in the books (see Literature), Cersei is the one who puts Joffrey in line for the throne by killing Robert and imprisoning Ned Stark. Though it is actually Joffrey who kills all of Robert's bastard children, out of the fear that one of them will try to claim the throne. Eventually, after all her children have died, Cersei crowns herself Queen of Westeros.
- I, Claudius: Livia will have her own family killed or banished if it means her son Tiberius will become emperor. Please note that Tiberius doesn't even want to be emperor. (Bonus points because Tiberius is only a stepson to Augustus—Livia's husband and the previous emperor—though Roman inheritance doesn't care.)
- Into the Badlands: Lydia is actively working to insure her son succeeds her husband Quinn as baron, even though Quinn himself doesn't think Ryder is tough or smart enough. But after one mistake too many, Lydia comes to agree with her husband and tells Ryder that he's not suited to becoming a Baron.
- An unusual heroic example: in Magnificent Century, it's the protagonist Hürrem who's scheming make one of her sons the next sultan… although to be fair, antagonist Mahidevran is doing the exact same thing. Hürrem wins... unfortunately the son that ends up winning is the Inadequate Inheritor, foreshadowing the decline of the Ottoman Empire.
- An example of Mother Makes You Queen occurs in Once Upon a Time: Cora manipulates events so that Regina saves the recently widowed King's young daughter and he takes Regina as a wife. It is also revealed she killed the previous Queen in the first place.
- In the Klingon house of Duras in Star Trek: The Next Generation, aunts Lursa and B'Etor who scheme to get their nephew Toral on the council.
- Catherine loves being the mother of the king. Deconstructed over time with her eldest son Francis, and deconstructed even harder with her second son Charles.
- Lord Darnley's mother's Lady Lennox is determined to make her son king by marrying him to a queen. She's quite proud of herself for this, but when she and Catherine meet, Catherine quickly declares herself the queen of this trope, pointing out that Darnley is only king consort, while her son is a true king.
- Sons of Anarchy: Gemma is shown to very much be pulling the strings on the men in her life. Women are not allowed to be members of the motorcycle club but Gemma always manages to be attached to the President of the club. Her first husband, JT, was a founding member. When he no longer wanted to live the outlaw life, it is implied that Gemma conspired with JT's best friend Clay Morrow, to kill JT so Clay could become President. Clay and Gemma married shortly after JT's death, making Gemma once again, the revered wife of the club president. Once Clay got older and struggled with arthritis which made it hard to ride his motorcycle, a requirement to be an active club member, Gemma began manipulating her son, Jax to take Clay's place. Many considered Jax the rightful heir to the club Presidency, even referring to him as the crown prince, but Jax was only 15 at the time of JT's death, too young to be an active member of the club much less the president. With Gemma's encouragement, Jax challenged Clay for presidency and won, making Gemma now the revered mother of the club's president.
- In Egyptian Mythology after her husband Osiris was murdered by his brother Seth who became Pharaoh, Isis made sure her son Horus could claim the rule from his Evil Uncle.
- In Celtic Mythology, when Fergus mac Roich married Ness, she gave him one condition: allow her 7-year-old son Conchobor to serve as a Puppet King for a year so that his future children could boast a royal lineage. Fergus agreed to her terms, and Ness immediately set about getting Conchobor a 100% Adoration Rating (as much by bribery as by good rulership) so that, when the time came for Fergus to reclaim his kingship, the people of Ulster told him to stuff it.
- The Bible:
- In the Book of Genesis, Rebecca tricks Isaac into giving Jacob the greater blessing that he intended to give Esau. An unusual example, since Rebecca is Esau's mother too; she just knows that Jacob is a more deserving heir.
- As King David is near death, his son Adonijah declares himself king, even though it had been prophesized that another son, Solomon, would rule. Solomon's mother, Bathsheba, works with the prophet Nathan to reveal Adonijah's actions to David and get Solomon on the throne.
- Queen Athaliah, who tried to murder the entire house of Judah so her sons could take the throne. She missed one.
- Subverted in the Ramayana—King Dasarath has four sons by his three wives, the oldest of which is about to be crowned upon the King's decision to retire, but on the day before the coronation, his favorite wife Kaikeyi (mother of the second-born Bharat) decides to call in a favor—after she saved his life in a previous war (she was his charioteer at the time), the king promised that he would grant her two wishes whenever she felt like it. She asks for the eldest son to be exiled and for Bharat, who was visiting his grandather at the time, to be crowned instead, forcing the king to either exile his universally beloved, virtuous first-born or shame his family's reputation for adhering to their word and dishonor his ancestors. The King complies with her request, but promtly dies of a broken heart (helped along by a previous curse incurred in his youth.) Once Bharat returns to find his father dead and his brother exiled, he's absolutely absolutely horrified, disowns his mother on the spot and, after much angst about being the son of such a wicked mother, waltzes off to find & crown his brother. As their father is dead and can't revoke his oath, the oldest prince feels obliged to serve his 14 years of exile, but once he returns after many heroic deeds, Bharat is all too happy to hand over the crown.
- In Pippin, Fastrada is scheming to get her son Lewis on the throne. She's cool will getting her husband and stepson killed to do it.
Lewis: Mama… if Pippin kills Father…
Fastrada: You'll be next in line for the throne, darling.
Lewis: But if Father discovers Pippin's plot and executes him…
Fastrada: You'll be next in line for the throne, darling.
- Queen Louveria from Final Fantasy Tactics. She confines herself to Offstage Villainy but her actions have ripple effects throughout the plot. If you read the character profiles over the course of the game, she eventually murders her husband and exiles/executes her way through most of his retainers just so her (possibly illegitimate) son has a better position in the coming civil war. She's apprehended and tossed in the dungeon of an impregnable fortress and the attempt to rescue her by her brother Duke Larg ignites the "War of the Lions".
- Long Live the Queen: Crown Princess Elodie's aunt Lucille—her late mother's sister-in-law—is trying to have her assassinated in order to put her own daughter on the throne.
- In Megan Kearney's Beauty and the Beast we learn from flashbacks that the Beast's mother attempted this trope back when he was a young man named Argus. She was the king's former mistress, Argus their illegitimate son, and she spent years secretly poisoning the queen to make her barren so the king would be forced to name Argus as his heir. When royal couple finally had a legitimate son, ruining her plans, she attacked her own son in rage, driving him to attempt suicide next to a magic fountain, leading to his transformation.
- According to Herodotus' Histories this happened with Cyrus the Great of Persia. His Grandfather Astyages, the King of the Medes, married his daughter Mandane to Cambyses the Persian as he thought Cambyses was unlikely to rebel. Later Cyrus is able to overthrow his Grandfather, starting of the Achaemenid Empire.
- Similarly happened with Xerxes (yes the God-King from 300). His Father Darius became King and married Atossa, daughter of Cyrus. There was dispute whether Darius' oldest son from his first wife or his oldest son from Atossa should be King. Finally Demaratus the exiled Spartan King said Xerxes should be King as he was born when his Father was King and he was descended from Cyrus. However this trope had potential to further happen according to Herodotus, who says he thinks without Demaratus Xerxes would have become King due to Atossa.
- Alexander the Great's mom Olympias is thought to have been this for him. After King Philip's death, she had his children by another wife, Cleopatra of Macedon, executed while Cleopatra committed suicide.
- The Julio-Claudians really were a Big, Screwed-Up Family.
- Livia Drusilla—third wife of the emporor Augustus—was accused by various historians of murdering most of Augustus' potential heirs so Tiberius, her oldest son from her first marriage, could succeed Augustus. This may be a case of Historical Villain Upgrade.
- Agrippina the Youngernote is thought to have poisoned her third husband Claudius so Nero (her son from her first marriage) could become Emperor and she could rule through him. Nero deconstructed the trope hard—within five years Nero was a Self-Made Orphan.
- Henry the Second of England, first King of The House of Plantagenet, became King due to his Mother Matilda, only legitimate surviving child of Henry the First of The House of Normandy. He had made her his heir, but his nephew Stephan with the help of the Barons made himself King, leading to a period of civil war in England. Matilda nearly became Queen, but it seemed the Barons wouldn't accept a woman ruler. Finally she agreed with Stephan that Henry would be his heir, which happened as Stephan died next year.
- The tenth century Roman noblewoman Marozia engineered the enthronement of her sonnote as Pope John XI. It is not confirmed that she was the one who had her mother's alleged lover Pope John X offed to place three of her candidates ending with her kid on the throne of Saint Peter but the Roman Church of the era had that sort of reputation.
- Isabella of France, known as the She-Wolf of France—living for years as a pious and dutiful queen consort to Edward II of England, she finally got fed up with his constant promotion of his favorites and his general incompetency, including callously abandoning her while she was pregnant. She left the country, gathered her own troops and her own lover, Roger Mortimer, and invaded England. She quickly had her opponents murdered—one had his head brought to her—and then brutally executed her husband's favorite Hugh Despenser. She then deposed her husband and placed her son, Edward III, on the throne and acted as regent. To round out the saga, she then supposedly had her husband secretly killed, in a legendarily horrific manner. She was later overthrown by her own son, who had Mortimer executed and sent her away to live the rest of her life in a monastery.
- The Ottoman Empire was a mess of this because (a) they didn't do the "eldest son" rule—any son had a shot, (b) a sultan's mother was effectively his queen, and the most powerful woman in the empire, and (c) with harems, sultans usually had sons with several different mothers, all of whom would be scheming against each other.
- Töregene Khatun was the Empress Regent of the Mongol Empire following the death of her husband Ogedei Khan, Genghis Khan's second son and heir, and pulled strings behind the scenes for years to get her son Güyük elected as Great Khan despite the attempts to delay the election by her nephew Batu. Unfortunately once she succeeded Güyük almost immediately turned on her, and among other things executed one of her closest advisers, a woman named Fatima, and Töregene herself died not long after under unclear circumstances.