RICHMOND, Va. -- Within the first five minutes of the History channel documentary "Gettysburg," a Union soldier splits open the skull of a Confederate with his rifle stock. Blood erupts from the wounds, splattering the camera's lens.

Would you expect anything less from Ridley and Tony Scott, whose resumes include "Top Gun," "Black Hawk Down" and "Gladiator"? The brothers behind some of the biggest blockbusters don't skimp on the horrors of war for the small screen in this docudrama.

"You know, when you're watching a documentary, the danger is to romanticize," Ridley Scott said. "There was absolutely nothing romantic about this war whatsoever, no more than any other war."

The Scotts' "Gettysburg" premieres at 9 p.m. on Memorial Day as History launches a four-year initiative to commemorate the 150th anniversary of the Civil War. Actor Sam Rockwell narrates the film, which is directed by Adrian Moat.

Scott praised Moat, but the Scotts' influence is apparent in the cutaways that explain the lethal qualities of new weaponry and, of course, the unflinching lens when metal meets flesh and bone.

"I think what Adrian went for was the hard facts, if you like, what it was like to be in the face of a hail of bullets, and also what it was like to face what essentially was new weapons," Scott said.

The battle, which blunted Confederate Gen. Robert E. Lee's bold invasion of the North, was fought from July 1-3, 1863, and pitted more than 165,000 troops battling in the hills of Pennsylvania. Casualties totaled nearly 50,000, the most from a single battle in the Civil War.

"Gettysburg" includes commentary from Civil War scholars such as Edward Ayers, president of the University of Richmond, and camera trickery such as soaring overhead shots to explain battle strategies.

It also focuses on some of the big personalities of the battle, such as steely Lt. Col. Rufus Dawes on the Union side and the Southern firebrand Brig. Gen. William Barksdale.

But the documentary also pays attention to the troops.

They include Sgt. Amos Humiston, a Union soldier who died clutching a photograph of his children, and Pvt. Joseph C. Lloyd, a member of Barksdale's Mississippian Brigade.