Sir Arthur Hellsing

Sir Arthur Hellsing was the head of the Hellsing family, the partner or husband of an unknown woman, and the father of Integra Hellsing

Appearance
In The Dawn, Arthur is depicted as a youthful man, likely in his early-to-mid thirties, with blonde hair and pale green eyes. In Ultimate, Arthur's eyes are bright blue, and his hair is almost platinum blond, most likely due to his old age. In The Dawn, he has two hairs that stick up on either side of his head, resembling horns. This characteristic is also found in Abraham Van Hellsing, who is his grandfather. Later on in life, he grows facial hair and a fringe falls over his eyes.

Personality
Arthur was cocky and amorous as a young man, with women he'd invite over sometimes briefly interrupting important conversations, as seen in The Dawn. He also seemed sloppy, as the library was in a state of disarray as well having dirty crockery stacked and shrewn about the place. Still, he ran the organization efficiently and was particularly wary about using Alucard for missions, utilizing the family servant sparingly and eventually not all. He might've been similar to Integra in some regards, as Alucard exclaims that "you ARE your father's daughter" implying a close likeness.

Early Life
Little is known about Arthur. He is a descendant of Abraham Van Hellsing and had a brother named Richard Hellsing. It is unknown who his parents were, or who the identity of the woman who would become Integra's mother is. When he was a young man, he became friends with his future colleagues Sir Hugh Irons and Sir Shelby M. Penwood. He would eventually succeed as the Hellsing family's new head.

Hellsing: The Dawn
During the events of Hellsing: The Dawn, he assigned 14-year-old Walter C. Dornez and Alucard to destroy a vampire research facility in Warsaw, Poland to stop the Nazis from deploying experimental Ghouls into battle. If allowed to continue, the Ghouls would keep growing infinitely, as defeated human infantries would have become ghouls. Despite doubt from members of the Round Table, Arthur was sure that Walter would succeed in the mission. According to Sir Hugh Irons, Arthur came to believe that Alucard was "too powerful a drug to be used as more than the occasional medicine", and Alucard was sealed and locked in the Hellsing Mansion's dungeon in 1968.

20 Years Later
Over the course of the next 20 years, Arthur had a daughter named Integra. In 1988, Arthur contracted an incurable disease. On his deathbed, Arthur entrusted Integra as the new head of the Hellsing Organization, much to his brother 's displeasure.

Integra
Arthur cared deeply for his daughter, teaching her the ways of the Hellsing organization, the whys and whats of demons, and grooming her to take his place. Despite her young age, he trusted her over his brother Richard Hellsing and declared her his heir on his deathbed

Integra's Mother
At some point in time, Arthur met a woman of Indian origin and settled down with her long enough to have a child: Integra. It is unclear exactly what kind of relationship they had, although during his tenure as Hellsing's Head, Arthur kept a photo of her holding their daughter on his desk.

Alucard
Arthur and Alucard's relationship is never explored in depth. However, he sees Alucard's power as a "drug" of sorts and eventually locked him in a dungeon for two decades. Yet he has a surprisingly deep understanding of Alucard and vampires, referring them as "frail, sobbing children" deep down. He also entrust Alucard to be Integra's "safeguard" if things should ever go wrong for her.

Walter
Arthur and Walter's relationship is unclear, although since Walter has no parents to speak of, it is quite possible Arthur adopted the boy. He also has deep confidence in Walter's ability, proudly referring the boy as "the strongest anti-monster human expert"

Sir Irons
Hugh Irons and Arthur were close colleagues with somewhat conflicting personalities. While Irons was all work and business, Arthur took an interest in chasing women and trying new things to complete missions, deploying the young Walter C. Dornez even against the suggestions and opinions of The Convention of Twelve.

Sir Shelby
According to Integra Hellsing's flashbacks, Arthur and Shelby Penwood had much the same relationship his daughter and the man would have. In particular, both had the tendency to ask for expensive and ridiculous items such as new guns or helicopters. Aside from that, the two were good friends.

Trivia

 * Arthur's eyes have, in different media, been one of three colors brown, yellow, and finally blue.
 * Arthur was in his 30s in 1945 and he was also older than Walter, who was 69 in 1999. That would mean he was in his 60's when he had Integra and died in his late 70's. This also means that there is a huge age gap between him and Integra's mother.