TV Anime
Commander Peter Fargason
Formerly a highly decorated British Army Captain who fought in the Gulf War, he became the commander of Hellsing's forces in the field. He was dubious about Seras' potential at first, observing that she'd been treated with kid gloves in D-11; and he's the one who pushes her the most on a day-to-day basis.
Fargason is well-respected by his men and his boss; he becomes one of Seras' string of father figures. He generally leads with a cool head, and reasonably but firmly tells off the press during the final battle of the TV series.
After taking some abuse from Jan Valentine and being retrieved by Seras, a somewhat dazed Fargason remarks, "I believed that man could conquer all the world's monsters . . ." "I'll listen to your story later," is Seras' sharp reply. She never gets the chance; the story dies with him.
Captain Gareth
Seras' direct superior in the beginning of the series, described later by Integral as "one of my best men". When they're trying to corner gay wonder vampire Enrico Stilvaletti, Seras has the rifle and Gareth tells her when to shoot; Seras has the super hearing and Gareth has the data to explain what she hears.
Since this is Order 03, Gareth gets stabbed by Anderson out of the blue. He fulfills a similar fuction to that of the Men in Black: he dies to demonstrate that Anderson is serious. He was at least useful beforehand, though.
Captain Steadler
Hired to replace Gareth, he came to Hellsing with high recommendations, and Fargason was impressed by his résumé. He doesn't live up to expectations.
Seras knew something was wrong from the beginning, but Steadler's sleazy overtures to her were straining her control. With some prodding from Alucard, she worked out that Steadler was collaborating with reporter-girl Kim to break the shocking story of Hellsing to the public.
"Don't you ever get sick of it?" he burst out as Fargason was slapping on the handcuffs. "You go and risk your life for this country, but this organization hides and you're treated like you don't exist."
"I think I seriously misjudged your character," was Fargason's steady reply.
Captain Chris Pickman
This guy wins bonus points for managing to hold out until the last episode. He seems younger than the other captains: complaining in the field, whacking ghouls with the butt of his gun, grinning as he tosses a grenade into a freak-filled room.
Still, even this tough guy is impressed when Alucard walks out of the aforementioned room in the wake of the explosion.
He dies in the battle at the Tower of London; Alucard comes across him sitting against a fence with a bullet in his stomach. Pickman asks a favor: "I want to be human. For Hellsing." Alucard approves, and delivers a killing blow that will make sure he stays dead.
Nameless Order 07 Chick
Meet the pretty young woman who takes the place of Officer Al in the manga. She appears in Order 07 to bring Walter photos of Anderson's barriers, snapped in town just an hour before.
This triggers the coded warning that gets sent to Integral at the National Gallery ("Captain Hook is moving to engage Tiger Lily and the Lost Boys"); Integral and Alucard then act on it.
She's still alive after the Valentine Brothers' assault, and she's an information handler, so she would've survived the catastrophe of the last few episodes. Which means she managed to survive the entire series. Shouldn't she at least get a name for her efforts?
She's voiced by Ayako Kurosaki and Siobhan Flynn. There's a place to start. Or we could start calling her Tinker Bell.
Dr. Trevelian
The surgeon who, with the aid of two nurses, operated on Integral in a hastily constructed sterile environment in the middle of her office.
He's calm and methodical, exactly as you'd want a surgeon to be; the coolness of the little sterile white tent and green hospital scrubs provides a perfect contrast to the heated, dark, bloody dream Integral is having.
Integral evidently knows him well; when she regains consciousness, he asks, "Do you know who I am?" "Dr. Trevelian," she replies. Family doctor, or perhaps Hellsing's on-call surgeon?
The Queen's Envoys
Only one has a speaking part, and he's credited as "Messenger". These two form the classic visual duo of the tall thin one and the short fat one.
They are not Hellsing members per se, but fellow servants of the Queen. Their mission is to delivermessages from her to Sir Integral in person.
Their messages are diplomatically phrased, and Integral never shoots the messenger, but they're not always as mild as they sound: she correctly interprets "Stay strong through this long night" as "You're on your own in this one."
The Grunts
The crowd of anonymous soldiers who look at Seras askance at first, and are most often seen in face masks that make them interchangeable. (It's very convenient for the artists.)
Unlike the all-male Wild Geese, there seem to be a few women among the ranks. (Check out the ponytail.) But none of the female soldiers ever get a speaking role, or even a derisive-smirking role; it's very possible that the only people who gave any thought to gender equality were the background animators. All the officers, as mentioned above, are of course male.
The Servants
We never see them around. There are no scenes with Seras accidentally encountering them, though she runs into Integral in awkward situations often enough. They're never off to the side while the main characters act; the Hellsing mansion always seems huge and empty.
And yet, in the very end, when the Hellsing organization has been publicly accused of treason and police are descending on the mansion, squad cars surrounding it like fireflies . . . in the end, we see a couple of frightened maids and a cook off to the side, guarded by a spare officer.
So apparently Walter doesn't keep the mansion in order all by himself. Aw.
Manga
Officer Al
We can only guess at his name from the Engrish barely legible on his name tag. It looks like Dextely Alphensys; maybe Dexter Alphonse? Perhaps it's an allusion to Alfred? Let's just call him Al.
We only see Al once, in his capacity as messenger boy. He's the one who arrives with the latest intelligence report, breaking the news that Iscariot has deployed its own one-man army, Father Alexander Anderson. He appears in two panels, and in the next one he looks twenty years older. Poor guy. The stress must've gotten to him.
The Men In Black
Bayonet fodder, plain and simple.
In preparing to go to Patrick and interrupt the battle between Alucard and Anderson, Integral asked for a gun, a sword, and two men. The gun destroyed a couple of Anderson's bayonets; the sword blocked a couple others.
The men pretty much just died.
I'm not really sure what the point of them was, except to demonstrate Anderson's willingness to slice up anyone in his way.