Disclaimer: I own nothing

A/N: Yay, my first Kuroshitsuji story! I've never written anything like this before, so I hope that I'll do a good job. I'll try to keep everyone in character. Though if Sebastian seems ooc in some parts, I remind you that we don't really know what he's like outside of his butler-persona.

Enjoy! And please excuse the fairytale-like opening. Btw, demons age A LOT slower than humans.

For demons, family bonds usually weren't very tight. As mostly solitary creatures, it was a nuisance to have other people around and have to share food. Most parents actually killed their off-spring in order to preserve resources. Besides, there were enough demons in the world already. But in some cases, having a child was absolutely necessary. Such a case was the royal family.

The king had been on the throne for as long as anyone could remember. He was very strong and wise, but as he became older his cruelty increased. He would send diseases and cause wars in the human world. He would randomly slaughter his own people just to see their blood spill. His wife feared that an enemy might come to destroy him one day, so she decided that they should have a child in order to keep the throne safe. Although the king was loathed the idea of children, he saw sense in her plan. And so they had a son, a beautiful boy with black hair and red eyes. The queen loved him from the start, but when the king looked at him he only saw his good looks and youth. Those traits caused the king to resent his son.

The boy fit the role of "prince" perfectly. As he grew he became more and more handsome. He excelled in his studies, music, and art. He was very wise and he knew what was best for his people. He was so cunning, even the most pious humans would sell their souls to him. All of the women wanted to be with him. By the age of one thousand, he was absolutely perfect. Well, to most people anyway.

His relationship with his father had never been very good. To him, his son was just a constant reminder that he was getting older and weaker. He also saw how the way the people of the kingdom adored him. The king would often berate him, saying that he wasn't worthy to be king, let alone his son. He would humiliate him and often spread rumors about him throughout the castle. If he didn't do something exactly the way the king wanted it, he would have his son beat in public. He would complain about him to the queen until she, too, came to hate him.

Unfortunately for him, he didn't see the way his son would glanced at the throne or the crown enviously. He didn't see how his son's eyes would would at him in a calculating way and the smirk that sometimes appeared on his mouth. You see, the prince was planning on taking his father's throne. He knew that everyone secretly hated his father(including himself). He also knew that many people wanted him as king, and that he had the skills and knowledge to do it. He had built up a secret army and several strategies over the years. He just needed the right moment to strike.

The moment came one night after he returned from a fencing tournament. He was going to his mother's room to tell her how it went. But when he knocked on her door he didn't receive an answer. The queen was usually in her apartments at this time of day, so this was rather odd. After hesitating a moment, he opened the door a bit and looked inside. He immediately wished he hadn't, for he saw his parents in a rather...intimate position. They were sleeping side by side, but it was obvious that they weren't wearing any clothes. The prince took a step back, but the noise caused his father to wake up and see him. The king immediately became furious and shot a bolt of fire at his son. The prince managed to prevent serious harm from coming to his body, but he was still singed badly. As he ran out of the castle he realized that his chance had come. He didn't want to go down in history as a tyrant who stole his father's crown. So his father attacking him like that was the perfect excuse to wage war on him.

He set up his base in a fortress that he secretly built in the mountains. When it became known to everyone what he was doing, many of the people came to support him. With a strong army, cunning mind, and support of his people, the prince was sure to reign victorious. But he didn't realize just how strong the king's army was. Although he was hated, he was still the king, and when there was something he hated, it was destroyed. Their armies were equally matched and fought for months without getting anywhere. Then something happened that would change everything.

The queen had apparently left the castle and was seeking him out. He immediately thought it was a trap since he knew that she had sided with his father, but he allowed her into the fortress anyway. He was shocked when he saw her, because he had never seen her looking so scared and unkempt before. He had also never seen her abdomen so round before. When he questioned her, she revealed that she was pregnant. When the king had found out, he tried to kill her so he wouldn't have another child that would betray him. She managed to escape him and decided that her son was the best person to go to for protection. She would even give him the child if he wanted.

He allowed her to stay for the sole reason that he was curious about his unborn sibling. He had spent many years as an only child and had never thought of having a brother or sister. He also realized that if he raised the child himself, there would be little to no chance of it betraying him one day. The queen was very old, and her second pregnancy was taking its toll on her. She was bedridden for many months after she arrived. The prince only went to visit her to see if her child was still healthy. He kept her in a small, dark, yet heavily guarded room with nothing to do. On occasion, he would have her interrogated to see if she knew any of his father's plans. She was often miserable, which brought a smile to her sadistic son's face. He was never the forgiving type.

On the day she went into labor, he could hear her screams of pain from a mile away. When the child was finally born the prince ordered that it be brought directly to him. It was a baby boy who was almost cherubic in looks(something only royalty could accomplish). He had blue hair and beautiful blue eyes, which was unheard of. Demons usually had either red, yellow, or black eyes. As he looked at his brother, a sudden feeling of warmth came over him. He held the baby close and bent his head down to nuzzle him, which caused the baby to coo and tug on his hair. Suddenly, a doctor came from his mother's room. The doctor told him that the queen was unwell and if she didn't receive the proper medicine-which they didn't have- she would die soon. The prince took another look at his brother before telling the doctor to leave his mother be and walking away. The queen was dead within a few hours.

The prince was surprised to find that he actually loved his brother. He hated his father and he was only on civil terms with his mother. But he actually felt a bond with this angelic looking demon, and he devoted all his spare time to him. He taught his brother to do everything from fighting to music to etiquette. And his brother seemed to like him and no one else. He would be very affectionate with the prince but only showed strained politeness to others. The prince was also happy when he saw the the child's demon mark was located in his eye. This meant that he would become very powerful one day. Powerful enough to help defeat their father.

After fighting for nearly four hundred years, the prince's armies finally gained an edge. The prince decided that this was his chance to finally dispose of his father. After borrowing power from his brother, he led his men to his father's castle. While they fought, the prince sought the king out. It seemed the king had been expecting him though, because he held a large sword and shield. Under normal circumstances, they would be evenly matched. But with the extra power from his brother, the prince managed to, finally, kill his father.

Despite what he thought, not everyone in the kingdom wanted the old king gone. He actually had a secret group that vowed to protect him. They were very angry at the prince for his treachery, so they began to plan their revenge. On the day the prince was to be crowned king, they moved their plan into motion. They managed to lure the younger prince away from the throne room to a more isolated place in the castle. Once there, they performed a spell that would change him into a human with no memories of his demon life. They figured since the older prince got rid of the most important person in their lives, they would get rid of the most important person in his life.

When the new king discovered what had happened, he was beyond angry. He sentenced the group to be tortured by the most sadistic people in the kingdom for the rest of their lives. His rage also created a disease in the human world which killed millions with a few short years. When a demon feels extreme emotions, their dark energy leaks out and causes havoc. He enjoyed taking his pain out on these creatures. He knew what most of them were really like and felt they deserved it.

He vowed that one day he would find his brother and bring him back home. Even if it took the rest of time. Until then, he would be the best king he could be.

A/N: Long prologue is long. Seriously, I didn't think it would turn out to be this long.

And that my children is the story of how Sebastian spread the Black Death. Okay, jk. This is the background for the rest of the story. Next chapter will have the same Ciel and Sebastian we all know and love. And dialogue!

Remember, if you have any suggestions or comments to leave a review!