Things change and never stay the same. Hoping to write themselves into history, the Konami group KCEN in 1998 created Castlevania Legends, said to be the storyline origin of the famed series. Following in the heels of titles like Bloodlines and Symphony of the Night, KCEN was intent on broadening the series' scope by further linking it to popular literature and the real-life misdeeds of both the genuine and fictional versions of Vlad Tepes Dracula. As such, the events of Castlevania Legends, positioned in 1450, are meant to coincide with the death and unholy rebirth of Vlad Tepes as the vampire Count Dracula, following along to at least one set piece from the novel Bram Stoker's Dracula.
Castlevania: Lament of Innocence, introduced five years later by the Konami group KCET, threw a wrench into the since-defunct KCEN's plans. The team responsible for Lament of Innocence, led by current series director Koji Igarashi, dismissed Legends from the official lineage for reasons that went unexplained for another three years. By the time titles like Curse of Darkness and Portrait of Ruin arrived, we came to know why: Igarashi, in an almost obsessive-compulsive manner, was hell-bent on justifying a profile he had authored in Symphony of the Night's instruction manual that had Vlad Tepes Dracula listed as "estimated to be 800 years old." Clearly the math didn't work by Legends' account: If Symphony is placed in 1797 and Legends in 1450, we have a separation of only three hundred years. To arrive at the desired longevity required something many dreaded--the admission by Igarashi that Lament's Mathias was Count Dracula, having simply changed his name by around 1476, the time of the real-life Vlad Tepes' death. This killed any logical connection between the series antagonist and its real-life counterpart and as a result marginalized Legends, which according to Igarashi has no place in the timeline.
But as I said: Things change. There are in reality many ways to squeeze in Legends, and more importantly the exploits of its heroin Sonia Belmont, and still have it function under the official timeline. For one, said timeline (packaged in as part of Portrait or Ruin's pre-order bonus) asserts that Mathias over time earned the name "Dracula" ("son of the devil") in light of his murderous impulses but did this before the name-change to "Vlad Tepes," the name under which he became most distinguished; therein, it's still very likely that Sonia could have confronted a Dark Lord who had not yet attained mass infamy (in a tale that would go largely unnoticed and thus unheralded).
It would happen like this: The young Sonia Belmont was a native of Warakiya (a storyline-based Romanian/Transylvanian region in Wallachia). It has been said that Sonia was trained by her uncle, who left to her possession the Vampire Killer whip. While her uncle was undoubtedly a warrior, there is no evidence of his battles, which means that he, like those before him, could have also fought against Mathias, or he could have remained idle, simply a link in the chain. It's clear from gauging the preambles to titles like Dracula's Curse that the family had been deemed a danger to the community and later banished, which might also entail a falling out with the Church; this would exclude Belmonts post-Leon but pre-Sonia from battling in wars like those fought during the Crusades, which involved skirmishes with the Ottoman Turks, who were expanding their jurisdiction at will. (Interestingly, had Legends' tale withstood as an encounter between Sonia and a reborn Vlad Tepes, it would be possible for a Belmont warrior to have once fought in the same company as Vlad, which would have been an eerie case of intertwined destiny.) In reality, despite public rejection, the Church eventually allied with the early Belmonts, whose ancestor Leon fought in its name, and became a guiding influence; with this degree of separation, as simply "allies," there would be no obligation for Belmont warriors to fight in any holy wars as Leon once did.
Noted series history (the instruction manual of Castlevania III: Dracula's Curse) speaks of someone called the Poltergeist King who "gave the mystic whip (Vampire Killer) to the Belmonts." We know that Rinaldo Gandolfi created what would eventually become the Vampire Killer, but we don't know who the Poltergeist King is. Many say that western localization confused certain issues and created a character that wasn't meant to be, but there is precedence for such a divine being, as a "corrector," in a series where a family's lineage is always threatened (like in the case of Nathan Graves and the Morrises, which we'll cover much later). Without a clear definition, we'll call the Poltergeist King a divine family ally. Should the family lose its way, with the weapons falling into the hands of those not equipped to brandish them, the King would in the absence of a responsible elder find for them a suitable host; this is so because a ready hero is a must, as the presence of great evil necessitates a greater good (thus why powerful forces struggled for Alucard's soul around the time of Symphony).
So when monsters began to terrorize the countryside and no one really knew why, Sonia was ready to step forward with the Vampire Killer, which with Sara Trantoul's spirit came to sense evil and over time afforded Belmont heroes this same sense. But she'd need more--a sub-weapon or five. The problem? The weapons, which Leon had found long ago, had since been lost. In order for Sonia to gain an edge, they'd have to found. The question: Could the whip, sharing some of the same magical energies, come to sense these lost weapons and lead Sonia to them? Something did just that, as the young Belmont was able to retrieve four of the weapons (the axe, the dagger, holy water and the cross) while exploring the castle and its outer regions. While Sonia never found the crystal, she did discover in its place a strange stopwatch that would one day be of use. Though, since she was not yet trained to use such weaponry, she instead utilized as sub-weapons her own natural inborn soul power, which allowed her to harness fallen spirits and transpose them into weapons of varying effectiveness. In deference to these soul powers, it would be the Vampire Killer and the five traditional weapons that she would pass on to her offspring for their future wielding.
One thing is for sure: On her seventeenth birthday, she met up with Alucard, son of Mathias Dracula, who at this point time was still in the early stages of his campaign to eradicate humans from the face of the Earth. Much earlier, Mathias had after a decades-long search met Lisa, who he believed to be the very reincarnation of his late wife Elisabetha. The relationship that followed planted the seed for the birth of Alucard, whose real name, as dictated by his father's soon-following name-change, is Adrian Farenheights Tepes. Much to Mathias' chagrin, his genes weren't as dominant as expected; as a half-breed, the procreation of a vampire and a human woman, Alucard grew at all times nurturing an inner struggle, a tortured existence he could hardly bear. His only means of control: Lisa's gentle and loving traits began to manifest within him a sense of justice counter to the teachings of his father, who thought himself to be training a future lieutenant in the war against the humans. Alucard's increasing resistance to his father's dark ways became more and more evident to the point where a split was inevitable. To Dracula, such a sudden action evoked a sense that his son was a half human, half vampire timebomb.
How, exactly, Alucard spent his childhood before breaking away to follow his heart remains unknown. Two unlikely sources, Nintendo Power and the cartoon Captain N: The Game Master, insist that Alucard did serve under his father as part of the famed underworld army, but his confused emotions, which he came to quell somewhat by adopting a do-the-right-thing mentality, sparked a parting of the ways that was anything but amicable. Thus, having divorced himself from his past, he became the "estranged and forgotten son of Count Dracula." His mind clear, Alucard vowed to put an end to Dracula's grievous scheme. In either case, so much is clear: Dracula had to be stopped, Alucard knew, and help was desperately needed. Though, there was in Alucard a hesitancy to fight his parent, as much a part of himself, which is more the reason for Alucard's seeking of an ally whose fighting presence might lessen the burden.
Alucard never did meet up with his father for the confrontation he dreaded. Upon meeting with Sonia in the castle's intimidating keep, whence she insisted that it was her job to vanquish one such as Dracula, Alucard put the notion to the test with an impromptu duel with his beloved. After impressing upon him her will--which convinced him that, yes, it was a task better left in her willing hands--he revealed a source of his pain: He believed strongly that he, like his father, was just as much a threat to humankind just by his very existence. There was a final part to his plan: Its finality would be marked by the submerging of his powers, the placement of his spirit into a state of eternal rest. The last vestige between the two involves the birth of Sonia's son following her triumph; that is, Alucard is almost sure to have impregnated Sonia during their time together.