In life, Strahd von Zarovich was a respected and decorated soldier. He was born in the long-gone human kingdom of Svitar, which was known for its military prowess and religious fanaticism. His father, Count Barov, was a decorated military leader. Barov was a cold man who found delight only in war and conflict. His two eldest sons, Strahd and Semyon, were enlisted in the military at the age of seven. The older, Strahd, served his father directly as a squire. From a young age, all Strahd knew was violence and pain, and he was told this was his inheritance. Svitar was often at conflict, particularly with Nortenia, a country bordering it to the north.
The Countess Branwen, didn't care for the battlefield, and mourned what she considered the "loss" of her two eldest sons. She kept her youngest son Sergei, at the time only a boy, close to her side away from the battlefield. Strahd grew envious of the love and attention Branwen visited upon his youngest brother, and even when he might have been permitted to stay home, chose to stay away on crusades for a long period of time.
When Strahd was just twenty,
Svitar was invaded. At this point, he was a general in the Svitaran army, Semyon a soldier, and Sergei still a babe. The war was long and bitter, and the Nortenians took more and more of Svitar under occupation as the years went on. Count Barov died defending the capitol while Strahd was occupied elsewhere, and the Countess and Sergei took shelter in a Grand Temple of the Morninglord, able to occasionally send letters to Strahd.
Strahd fought the Nortenians for many long years. Eventually, he fell back to a nameless valley in the mountains where his mother had been born, with the intention of taking it back from the occupying Nortenians
Strahd was eventually able to triumph over the pursuers. Having spent much of his youth and what little free time he allowed himself in the valley, he was far more familiar with the land and was able to out-manuever his opponents. The defining act that secure the valley, however, was a deal he made deep in the mountains with
a nameless, faceless dark power, and the steps he took to unseat
its rival.
Victory was bittersweet. The country of Svitar was gone by the time his victory was secured, either occupied or absorbed by surrounding powers. The vast county his family had once ruled was shrunk down to a valley with a handful of towns within. Strahd had a castle constructed to be the seat of his family going forward, but it was a depressed and empty place, with his mother too ill to make the journey when it was completed. The wounds of war caused him daily pain. Still, he had soldiers and a handful of nobles loyal to him, and a land he kne was protected by more than men.
It was at this time in his life, when he was at the highest and lowest point of his life simultaneously, that Strahd met
Tatyana. A druid who had lived in the valley her entire life, she was a beautiful and gentle woman who had been dedicated to the local deity before the war. She was brought to the castle by Rahadin, who had been seeking ways to ease Strahd's chronic pain. Strahd was immediately taken with her, though she seemed oblivious to his affection.
It was during this time that Strahd received another blow: a letter stating his mother had passed, and his youngest brother was making the journey to Barovia with the bodies of their parents. Sergei's arrival was the worst culmination of all of Strahd's fears. A young and handsome man, untouched by the horrors and wounds of war, Sergei was beloved by the people immediately--and more importantly, he was beloved by Tatyana. Sergei and Tatyana courted, and Strahd's pride forbade him to interfere. As time went on, however, his mental health deteriorated, and the dark power he had bargained with began to whisper to him. So long as Sergei lived, it told him, his victory would never be complete. When Sergei died, Strahd would finally gain everything he longed for, and deserved.
On the night of Tatyana and Sergei's wedding, Castle Ravenloft was attacked by a nobleman who had come to Barovia under Strahd's banner, and now resented him. In the chaos, he slew his younger brother and drank his blood. In that moment, his pact and fate was sealed. Tatyana discovered the pair, and fled. Strahd pursued her, and the two came to blows on a balcony of the castle. In the final moments of her life, Tatyana drew Strahd close, plunged a dagger into his chest, and pulled them both down to death in the rocks below. Rahadin retrieved their bodies and buried them both in the
Crypts of Ravenloft. Following the orders laid out in a letter Strahd had penned that very night, he carried out the last step needed for the dark powers to control Barovia.
Five years to the day after his death, Strahd rose from his coffin. On that day, a heavy fog rose from the earth and enshrouded the valley. From that moment, the valley was cut off from the rest of the world, pulled into a Dread Demiplane ruled by misery.