Genocide of the Saiyans is the very brief but incredibly disastrous conflict between Frieza's forces and the Saiyan race. It should be noted that "Genocide of the Saiyans" is not an official term, but commonly used.
Having been asked to destroy Planet Vegeta by the God of Destruction Beerus, and also due to hearing of the legends of the Super Saiyan and Super Saiyan God, Frieza decides to eliminate the Saiyan race to avoid any threats to his rule. He has an order sent out to command all Saiyans to return to Planet Vegeta.
Upon arriving back, Bardock realises that Frieza may be planning to wipe out the Saiyans, and so he and his wife Gine choose to send their young son Kakarot away to Earth to keep him safe. The Saiyan prince Vegeta and his ally Raditz both hear the call back but choose not to respond to it, and stay on the planet they were conquering. Nappa - the general of the Saiyan army - also remains on his mission and does not return to the planet within the allotted time.
King Vegeta, supreme ruler of the Saiyan race, had been plotting to save his young son from Frieza's grasp and to attempt to defeat Frieza and reclaim his rightful throne over his people. On the day that the genocide takes place on, King Vegeta gathers his most powerful Saiyan elites and launches an attack on Frieza. Vegeta and his elites arrive on Frieza's spaceship and after killing numerous guards, successfully push their way into Frieza's chamber. However, upon arrival, King Vegeta's men are so stricken with fear, they cower behind their leader.
King Vegeta, alone, launches his attack on Frieza. Frieza effortlessly dodges a swift punch from the Saiyan king, and with an amazing display of power, kills the king with a single punch to the jaw as Zarbon and Dodoria bear witness. Frieza then also slaughters Vegeta's elites, and finally informs Zarbon and Dodoria that it is time to extinguish the Saiyan race with one final attack.
As Frieza's ship looms over Planet Vegeta, the final hour arrives. Bardock flies up toward Frieza's ship, in the hopes that he may be able to thwart the tyrant's attack. After witnessing Bardock's approach, Frieza orders his army to be released and to engage the lone Saiyan warrior. After killing numerous soldiers, Bardock eventually makes it to Frieza's ship, and calls the tyrant out for one final confrontation. Frieza then appears from his ship, comfortably sitting in his hoverchair.
After informing Frieza of his people's separation from Frieza's empire, Bardock launches a powerful energy ball (Final Spirit Cannon) at the tyrant. However, Frieza, with the lift of a finger, creates a massive sun-like energy ball, his Supernova, which he launches at Bardock and the planet below while maniacally laughing. Bardock is obliterated by Frieza's attack, along with may of Frieza's own soldiers close by. The energy ball then proceeds to slam into Planet Vegeta, and after burying itself into the planet's core, Planet Vegeta blows up, killing nearly the entire Saiyan race in the process. Observing the "beautiful fireworks", Frieza laughs and congratulates himself on his new found "accomplishment" before leaving in his ship to continue business as usual. In a single day, the mighty Saiyan race was drawn near complete extinction.
Far away in space, a space pod containing a baby by the name of "Kakarot" lands on Earth. He is found by an old man named Gohan, who takes the child in and renames him, "Goku". This young boy would grow up into the powerful warrior who would one day prove the Super Saiyan legend true and reclaim his race's honor by defeating Frieza over two decades later. Prince Vegeta, the young son of the now late King Vegeta, and his aide, the Saiyan army generalNappa, also survive, as they are on an assignment when the planet was destroyed. Upon being informed by a soldier that his planet collided with a large meteor and was destroyed, Vegeta's simple response is nothing but an "oh... really?", but this event would come back to haunt him many years later. Raditz, Goku's older brother and the first son of Bardock also survives, due to being with Vegeta on an assignment. Although a story about a meteor shower was fabricated to cover up Frieza's true involvement in its destruction, rumors about Frieza's genocidal action towards the Saiyans still persisted, eventually reaching the ears of Nappa, who attempted to tell Vegeta shortly after being brushed off for their accomplishment of the subjugation of the Shikks.
Other survivors include Turles, a Saiyan who escaped and left Planet Vegeta many years before its destruction. He went on to become a maverick warlord, but when he journeys to Earth, he and his team of mercenaries are defeated and killed by Goku. In the special Dragon Ball: Yo! Son Goku and His Friends Return!!, Vegeta is revealed to have a long lost brother named Tarble who comes to Earth seeking help against Abo and Kado, two remaining members of Frieza's army. Despite his place in the royal bloodline, Tarble's power level was considered weak and thus he was sent on assignment elsewhere by his father long before the planet's destruction. After Abo and Kado are defeated and reform, Tarble departs Earth. In the video game Dragon Ball Online, the Time Breaker Mira saves Bardock from Frieza's attack and takes him to the future to become one of Mira's minions. In the spin-off manga Dragon Ball: Episode of Bardock, Bardock somehow does not die, but is instead sent hundreds of years back in time to Planet Plant before the Saiyans arrived there. He confronts an ancestor of Frieza, the space pirate Chilled, and becomes a Super Saiyan in the process. Chilled's experience with the Super Saiyan is passed down to his descendants afterwards.
The destruction of the Planet Vegeta and the near extinction of the Saiyan race was mentioned in the 2013 movie Dragon Ball Z: Battle of Gods after awakening from his 39 year slumber, Beerus the God of Destruction of the 7th universe asks his attendant and mentor Whis if Frieza destroyed Planet Vegeta in which Whis replies yes without a trace left. Beerus revealed that he intended to destroy the Planet himself but ultimately couldn't be bothered as it was too far off for him to be concerned about. He was however surprised to learn that Frieza himself was beaten by a Saiyan named Goku in which he later hastily tracks down to ask about the Super Saiyan God.