Before The Taken King :
Prior to the events of The Taken King, Guardians crippled the Hive invasion force on Earth and the Moon by methodically taking down their field commanders and strategists, including Sardon and Omnigul. The Guardians then banished Crota's soul and eventually killed Crota himself. They also destroyed a Shrine communing with Oryx and killed its protector.

Eris Morn alerted the Queen of the Reef of Oryx's arrival, and the Queen set out with the Awoken Armada to Saturn, where the Taken King's Dreadnaught had stopped to refuel. Prince Uldren led his fighter wings to attack the Dreadnaught and engage the fleet of Tombships protecting it, with the Queen and Oryx presiding over the battle from their respective flagships.

With help from her Coven of Techeun Witches, the Queen summoned her Harbingers, deadly orbs that could decimate an army in seconds. The Harbingers bombarded the Dreadnaught, but after the explosions faded away there seemed to be no lasting marks on the battlecruiser. Oryx then fired the ship's superweapon, which ripped a hole through the rings of Saturn and completely destroyed the Awoken fleet. Queen Mara and many other major parts of the Reef's leadership, including Paladin Abra Zire and Techeun Shuro, have since disappeared and are considered MIA, while Petra Venj has advised a remaining Paladin to declare all of them dead.

Attack on Phobos :
Meanwhile, the Vanguard intercepts a distress signal on all channels, broadcasted from the Skyburner fortress of Korus on Phobos. A Guardian is dispatched to Phobos, and they witness a strange new enemy slaughtering the Skyburners. Oryx contacts the Guardians, willing into existence an army of corrupted Cabal and Hive called the Taken. The Guardian defeats these Taken, overcoming Syrok, the Word of Oryx. They then attempt to escape the Skyburner Keep via the Aerodrome landing pad, which is riddled with Taken. The Guardian reaches the transmat zone and is pulled back to the Tower.

From then, Oryx's master plan is revealed: He will enslave as many Cabal, Vex, Fallen, and his own Hive as he can, and use them to bring the system into ruin. Initially, one of his consorts, Ecthar (who also fluently speaks English), tells him to only retrieve the strongest of the four races and bring the rest to nigh-extinction, but Oryx objects to Ecthar's advice.

Realizing that the Taken are too deadly a threat to take lightly, the Vanguard send Guardians to rediscover lost powers of their forebearers. The Hunter gains the Nightstalker class and the Shadowshot super ability, the Warlock gains the Stormcaller class and the Stormtrance super ability, and the Titan gains the Sunbreaker class and the Hammer of Sol super ability.

Securing a Beachhead:
The Vanguard has discovered Oryx's Dreadnaught in orbit of Saturn, and has analyzed its super weapon. Hunter Vanguard Cayde-6 directs the Guardian to one of the dead Colony Ships in Old Russia, Exodus Blue, where he had previously hidden a stealth drive that could get Guardians past the super weapon into the Dreadnaught to face Oryx. Upon touching down in the Blast, just outside of the Fallen House of Devils' lair in the shadow of Exodus Blue, the Guardian discovers that the Taken have attacked Earth and are fighting the Fallen. The Guardian enters the Exodus Blue and accesses a service elevator to reach a platform. The Guardian then extends a bridge to the other spire of the Exodus Blue. After crossing the bridge, the Guardian fights past Fallen and Taken to the top, where they recover the stealth drive. However, a force of Taken warps in, led by an Echo of Oryx. The Guardian defeats the Echo and returns to the Tower.

With the stealth drive equipped, the Guardian approaches the Dreadnaught, remaining undetected by the super weapon. However, the drive unexpectedly malfunctions, and the Dreadnaught locks onto the jumpship and fires the superweapon. The jumpship is destroyed, but the Guardian manages to warp out onto the Dreadnaught just in time. They hunt down three energy links throughout the gargantuan Dreadnaught, each fiercely guarded by Taken. When every link is destroyed, the super weapon shuts down for good. The Guardian then finds a Skyburner gunship rammed into the Dreadnaught's hull, where the Cabal are locked in a fight with Hive and Taken forces. The Guardian establishes a transmat zone and takes down a Goliath tank, aided by Cayde-6, who pulls the Guardian out.

Hunting Oryx :
In order to find Oryx, the Guardians break into the crashed Cabal gunship, the Dantalion Exodus VI, and steals information that the Cabal have secured on Oryx. They learn of a portal called a Rupture that leads to Oryx's throne room. Tracking a scout team dispatched to the Rupture, the Guardians take out another Echo of Oryx and learn that the Rupture can only be traveled by those with Ascendant status.

To make a long, long story short, the lore explains the origins of the Hive race and Oryx himself - or, originally, herself.

The Hive trace their origins to a king that left behind three daughters: Xi Ro, Sathona, Aurash.

Things weren't going so well for the proto-Hive race. They were stuck living on shards of their former planet which had crashed into a toxic gas giant. Their numbers were dwindling due to predators and infighting.

Step up Aurash, eldest of the three sisters, who journeyed deep into the gas giant's core. She passed a friendly creature named the Leviathan, a disciple of the orb-like Traveller, then ventured further down to a dark race simply referred to as the Worms.

It was here that the three sisters made a pact with the Worms to join forces and morph themselves, becoming hosts for the Worms' larvae. The sisters would gain strength and new powers, but be bound to the Worms forever.

Each of the three morphed into new beings: Xi Ro into Xivu Arath, Sathona into Savathûn, and Aurash into Auryx (and once crowned, styled as Oryx) - a new king for the Hive.

Other Grimoire cards detail the fate of Awoken characters such as the Queen and her brother, last seen in The Taken King's opening cinematic.

There are 50 Calcified Fragments to collect, each with their own lore entry about the Hive. The details of these have been scooped up and can be browsed right now on Destiny Tracker. But players are still yet to find all of the game's Calcified Fragments in The Taken King itself - as well as other secrets. It may be a while before all of the game's story details emerge.