Davros was born during the Thousand Year War between Thals and Kaleds on the planet Skaro, the issue of a relationship between Calcula and Quested. It was a time when mercy and nobility were all but non-existent and life was harsh and grim. The use of atomic weapons and other agents of mutation had started to produce mutants known as mutos. As a child, Davros claimed only his mother believed in him. Others feared him and his determination, and were right to do so. His father wanted him to become a soldier like his elders, but Davros was determined to become a scientist.
Davros disagreed with his sister Yarvell's ideas of a compromise with the Thals. Davros was forced into the military where he was put in charge of developing new weapons. After his mother killed his father, sister and aunt, Davros no longer had anyone that he could impress. In honour of Yarvell's death he and his mother commissioned a statue to be made to house her ashes.
Davros began experimenting with organisms and teaching them to speak. In particular he taught them to say his own name. For his first experiment he used a Thal brain instead of a Kaled one.
Davros was grievously wounded by an attack, and afterwards he needed a mobile life support system. Thirty seconds without his life support would have killed him. The life support system was controlled by a switch conveniently placed on his panel of buttons on his life support system. With his equally ruthless aide Nyder, Davros ascended to a high rank in the Kaled Scientific Elite and presided over the creation of the Daleks. Intervention by the Time Lords began a chain of events starting with the the Doctor being sent to Skaro during this time period, where Davros first demonstrated the Daleks to the Kaled Scientific Elite. The Doctor and Davros first met at this time. Davros imprisoned the Doctor. He used a lie detector to force the Doctor to reveal the details of the Daleks' future defeats, so that he could learn from them and so that his creation, the Daleks, could avoid them. (The Doctor later had this record destroyed.)
The Daleks eventually turned on Nyder and exterminated him. Later, they apparently exterminated Davros himself, simply because Davros was not a Dalek. Ironically, they exterminated him (or so they thought) because they simply did what their creator programed them to do: exterminate all those who were not pure Dalek. They damaged his primary life support system, supposedly killing him. However, the secondary and backup ciruits switched on immediately which, allowed him to survive in a form of suspended animation while his life support worked to regenerate him. After an unknown period of time had passed, Davros was sought both by the Daleks, now a major galactic power, and by the Doctor. The Daleks sought to revive Davros so that he might offer them a way out of their impasse in their war with the Movellans. Davros' suspended body was found in the underground remains of the crumbled scientific elite bunker, and was revived. Davros opted to help the Daleks in their war against the Movellans. He devised a plan to destroy a Movellan ship but after this failed he was captured by the Doctor and escaped Dalek slaves and imprisoned in a cryogenic freezer as "a block of ice".
The Humans decreed an indefinite sentence of suspended animation, during which time Davros retained full consciousness. After 90 years, the Daleks, led by the Dalek Supreme, liberated Davros from his prison ship in space, and revived him once more. They believed that he might help them to find a cure for the virus with which the Movellans defeated them: a virus that attacks only Dalek tissue. Under the pretense of discovering the cure, Davros began experimenting on Daleks to bring them under his control. The Doctor, now in a new incarnation, attempted to kill Davros during this time, though he ultimately lacked the resolve to do so directly. His treachery discovered by the Dalek Supreme, Davros released the Movellan virus onto the prison ship, effectively killing all the Daleks on board. The virus then began affecting Davros, who promptly fled in an escape pod before Stien caused the station (and the prison ship) to explode.
Davros was then somehow picked up by a different space station and imprisoned in a vault. Arnold Baynes and his wife Lorraine extracted him and helped in his restoration. At the very same moment, the Doctor arrived after being called in by some friends. The Doctor demanded that Davros be immediately placed in suspended animation but as Davros was fully conscious he goaded the Doctor into doing the job himself. The Doctor couldn't. Feeling Davros deserved a chance for redemption, Baynes offered him a job at his company, TAI. The Doctor also offered beginning a working relationship with Davros. Eventually, Davros gained a foothold. He held great interest in the Stock Market and planned on closing it down, the results completely disrupting the Galaxy. Throughout this venture however, Davros began to be haunted by his past, particularly the time before his accident when he betrayed a female Kaled scientist named Shan who he perhaps loved. The Doctor was able to halt Davros's plan but he managed to escape in a ship. The Doctor managed to take control of the ship from the TAI control room and steered the ship around making it crash, Davros screaming Shan's name fearfully.
Davros, however, survived and set himself up as "The Great Healer" on the planet Necros and lured the Doctor there. Using the bodies of the dead at Tranquil Repose, Davros created a new race of Daleks with white and gold livery, who would later be called "Imperial Daleks". The new faction was totally loyal to him. The Supreme Dalek's forces arrived on Necros (having been brought there by Tranquil Repose's disgruntled staff) and captured him to put him on trial.
By the time of his attempt to recover the Hand of Omega from 1963 Earth, Davros called himself the Dalek Emperor (of the Imperial Daleks only). Apparently, he had lost most of his organic body, and was completely encased within an Imperial Dalek-like shell, though his head and upper body still appeared to be at least partially Kaled. He was apparently killed by the Hand of Omega but survived by once again by escaping in an escape pod.
The escape pod was taken on board by a garbage ship called the Quetzel. the Doctor and Sam Jones landed on the Quetzel. A Thal force later took control of the ship. They wanted Davros to alter their race so they could better fight the Daleks. A force of Daleks arrived and took Davros, the Doctor, Sam, the Thals, and the Quetzel engineer Chayn to Skaro, which Davros had believed destroyed by the Hand of Omega. The planet destroyed had in fact been a decoy world named Antalin. Now the Dalek Prime wanted to remove any supporters of Davros from the Dalek race. A trial was held. Those Daleks loyal to Davros turned on the Dalek Prime and a civil war broke out. In the end, the Doctor and his allies escaped from Skaro, Davros' forces were defeated, and Davros was apparently executed by matter dispersal. However, there is a possibility that the Dalek operating the unit was loyal to Davros, and may have transported him to safety.
Alone in space, Davros created the virus, capable of killing all living things, which the Doctor had hypothetically compared the Daleks to during their first conflict on Skaro. He was found by a Nekkistani ship. The Nekkistani helped him, and he rewarded them by killing them. The Nekkistani ship, with Davros on board, was found drifting in the Time Vortex by the Doctor, Gemma Griffin and Samson Griffin. Davros took control of Gemma and Samson and operated on the TARDIS after Samson obediently rendered the Doctor unconscious. Davros established a link to the TARDIS. He sent Gemma and Samson home and left the TARDIS to be damaged by the self-destruct of the Nekkistani ship. Davros went on to conquer Earth by causing mutations and creating new Daleks. By the time he met the Doctor again, Davros found himself teetering on the edge of sanity, his mind split between two warring personalities - that of Davros, and that of "the Emperor". The Doctor struck a deal with the Daleks, who considered Davros an unreliable leader, that they would leave Earth with their true Emperor if the Doctor did not release the virus. The Daleks accepted and left Earth with Davros, his Emperor personality dominant.
After this, Davros went on to be a commander of the Daleks in the Last Great Time War, only to supposedly die during the first year of the conflict (despite the Doctor's efforts to save him) at the Gates of Elysium, when his command ship flew into the jaws of the Nightmare Child. However, Dalek Caan broke the War's time lock and saved him from death. Davros then rebuilt the Dalek race by using a large number of his own cells, leaving his internal organs and skeleton exposed. Davros called these Daleks his "children".After Davros was rescued by Dalek Caan and had finished creating his new army of Daleks, he used a planet-sized ship known as the Crucible to travel the universe and "steal" planets. These planets were then put around the Crucible. Earth was the final planet to be taken by Davros and his New Daleks. They took the planets to the Medusa Cascade where he and his Daleks awaited the arrival of the Doctor in a pocket of time one second out of sync with the rest of the universe. Davros used advanced technology to hack into the wavelengths of the Subwave Network and talk to the Doctor, explaining to his nemesis how he had survived.
It quickly became apparent that Davros had once again become a slave of the Daleks, who placed him under guard within the Vault on the Crucible as part of a deal he made with the Supreme One. If Davros was indeed a slave, it is puzzling as to why there was a terminal in his prison in the Vault which could be used to control every aspect of the Daleks' travel machines and the Crucible, especially as it did appear to be operational by Dalek implements.
This was used by Donna and the Doctor to destroy the Daleks. This arrangement required Davros to build a Reality bomb powered by the Crucible and the 27 planets in the Medusa Cascade which would destroy all of existence leaving the Daleks the sole inhabitants of the universe. However, his plan failed due to the intervention of the Doctor and Donna, who destroyed the Dalek race once more, leaving Davros on a burning Crucible. Before leaving in the TARDIS, the Doctor offered to save Davros, but the creator of the Daleks refused, stating that he named the Doctor the Destroyer of Worlds, after which he was apparently engulfed in flames. To this point of time the BBC has still not confirmed whether Davros is truly dead.
Most notable of Davros' creations is the Mark III travel machine, which then became known as a Dalek. Davros also experimented with other Dalek forms, such as a Dalek able to walk over rough terrain known as a Spider Dalek.
Davros also created an Imperial faction of Daleks to counter what he saw as a Renegade faction of Daleks, as well as the cybernetic Juggernauts by combining Human components and DNA with the robotic Mechanoids.
Davros had a sound mind early in his life, but the incident that crippled him and his overall experiences in the Thal-Kaled war left him a depraved and ruthless megalomanic not far below the surface. Brilliant and driven, he relentlessly experimented to find the final form of the Kaled people. Davros was a cool and sadistic person; it was his ability to command and delegate that was most forceful and cold. While his conversation with the Doctor following his awakening suggests that he may have survived the extermination attempt through forethought, it does still seem to have made Davros even more bitter than he had originally been.
After his supposed death and rescue from the Last Great Time War, Davros arguably even seemed decidedly less power-crazed and somewhat defeatist, perhaps due to having lost control over the Daleks yet again as well as being aware that once he was of no further use to them, they would most likely exterminate him. He also seemed to have developed a dislike for pride and vanity, traits which he had always exhibited in previous incarnations. He admonishes the Dalek Supreme for displaying pride and distastefully notes the "arrogance" in the Doctor's voice. Ironically he himself goes on to exhibit pride, refusing to escape the exploding Crucible with the Doctor and instead chosing almost certain death. He also gave the impression of being more insane than ever, having been consumed by a nihilistic desire to completely destroy the entire multiverse, not alone the entire ever-expanding cosmos.
Davros was originally seen by the Doctor sitting upright in a movement and life support chair resembling the base of a Dalek. His skin was discoloured and his body has been crippled by some accident in his past. His Kaled body was similar to that of a Human, though a blue eye in his forehead replaced his lost vision, allowing him some semblance of sight. The overall effect made him look like a Dalek from a distance. A metal brace was attatched to his head, and several wires were plugged into his skull. Davros also had a throat microphone implant, to enhance his damaged voice. He had only his right hand, which he used to operate various controls on his chair. These in turn could perform various functions from controlling doors, the Mark III travel machines, or his own life support system.
Following his cryogenic imprisonment, Davros's face gained a yellowish, sagging appearance, probably caused by the effects of the time he spent in sub-zero conditions.
On Necros, Bostock fired a gun which destroyed most of his right hand and thus his independent ability to operate. For a short time after, his hand was replaced with a claw and finally replaced with a prosthetic substitute of future human design He was capable of projecting electric shocks from both his organic and mechanical hands, allowing him to ward off attackers and stun or even kill them.
At some point during or after the Time War, Davros would dispense with his skull wires and throat microphone, though retaining his head brace. (possibly due to having gained access to more advanced medical equipment, negating the need for such items)