Key point: These battles changed history and highlighted the shifting nature of modern war.

Short, frantic and bloody has been the history of aerial warfare. While human beings have killed each other on land and sea for millennia, air combat is but little more than a century old. Yet it quickly caught up with its older siblings. In 1903, the Wright brothers made their historic flight; by 1911, the Italians were bombing Libyan tribesmen; by 1914, the first dogfights occurred; and by 1918, German and British bombers were attacking each other's cities. By the end of the First World War, the newly designated Royal Air Force alone had 22,000 aircraft.

It also says something about the progression of aerial warfare that in  "Bloody April" 1917, when elite German fighter pilots like Manfred "Red Baron" Von Richtofen tore through British fighters, the British lost 275 aircraft. A quarter-century later, in July and August 1943, the Luftwaffe lost a total of 3,200 aircraft.

Since then, airpower has become an essential (some airmen past and present would claim the essential) weapon of warfare.

Here are five of history's greatest air battles:

Battle of Britain:

The most famous air battle is the Battle of Britain. Partly, this is because it has become a part of British mythology, and Britain produces a copious amount of military literature and movies, especially about Britain.

And partly, because the stakes in the summer and fall of 1940 really were dramatic. Previously, airpower had been perceived as merely an asset to help the ground forces. But the Battle of Britain raised the possibility that aerial bombardment could induce a nation to surrender (a notion that still hasn't totally evaporated in the United States).

It was water, not air, that mattered at first. The German army had swept through Poland and France like butter. If German troops could land in Britain, whose small army had been mauled in the French campaign, then the Nazi flag would fly over Big Ben.

However, standing between the German army and London—as it had stood between Napoleon and London—was the Royal Navy. The German navy was no match for it, but the Luftwaffe might prevail in a contest between airplanes and surface ships. Yet before the Stukas could sink the British battleships and destroyers, the Germans needed to eliminate the Royal Air Force fighters that would rise to protect the navy.

The Germans pounded British airfields, but still the RAF Spitfires and Hurricanes sortied to take a toll of German bombers, whose formidable Me-109 fighter escorts lacked the range to escort the bombers deep into England. The Germans then switched to bombing cities, especially London, with no better results. The Germans couldn't invade Britain, nor could they bomb it into submission. The cost of a three-month air campaign was almost 2,000 Luftwaffe aircraft and well-trained crews, as well as Hitler's hopes to end the war in the West and concentrate all his forces on conquering the Soviet Union.

Victory through airpower had failed, a lesson fated to be repeated many times.

Big Week:

The United States had to learn the hard way what the Luftwaffe had learned over England; despite prewar theorists who asserted that bombers could penetrate any defenses and compel the enemy to submit, it just wasn't true. The United States had pinned its hopes on a daytime offensive of massed formations of heavily armed B-17 Flying Fortress bombers that would pulverize German industry with high-altitude precision bombing.

Yet by the summer of 1943, even the Flying Forts were taking unsustainable losses from German fighters, including the disastrous Schweinfurt and Regensburg raids when sixty out of 367 B-17s were shot down. Bomber crews were promised they could go home if they completed twenty-five missions: their average life expectancy was about thirteen missions (flying at night wasn't any better; life expectancy for British night bomber crews was six weeks).

Meanwhile, the D-Day invasion of France was just a few months away, and with it, the prospect of contending with the Luftwaffe in the middle of the greatest amphibious assault in history. So American planners conceived of a bold idea: a massive aerial offensive against German aircraft factories. German fighters would naturally rise to the occasion, which is exactly what the Americans wanted. This time, the B-17 and B-24 bombers would be escorted by long-range P-51 Mustang fighters that had begun arriving in Europe in early 1944, as well as shorter-range P-47 Thunderbolts that had finally been equipped with drop tanks carrying extra fuel.

During "Big Week" of February 22-26, 1944, massive air battles raged across Germany. American losses were fierce; almost 250 bomber and thirty fighters. But the Germans lost more than 350 fighters. The Germans could replace the aircraft, but not the pilots. The Germans—and Japanese—had neglected to train adequate numbers of replacements. The new crop of Luftwaffe pilots would be meat for better-trained Allied pilots.

Most important, American fighters over Germany created a dilemma that the Nazis could not solve. Shooting down heavy bombers required heavily armed and armored fighters. But weighing down German fighters with extra cannon, air-to-air rockets and armor plate left them sitting ducks for the unencumbered, and thus more maneuverable, Mustangs and Thunderbolts.

There is still much debate over whether Allied strategic bombing was a war-winning strategy, a waste of resources or even a war crime. But Big Week wasn't simply about bombarding factories. It showed how an enemy air force could be placed in a no-win position where it either rose to certain defeat, or allowed its country to be destroyed.

Mig Alley, Korea:

The first battles of the Jet Age occurred over Korea, in a battle that pitted American against Soviet pilots in a taste of what World War III might have looked like had the Soviets invaded Western Europe in the early 1950s.

For a time, it looked like the Communists might actually achieve air superiority over American forces, something that never happened in the Cold War. The United States and its UN allies initially sent a force of propeller-driven World War II leftovers, such as the P-51 Mustang and B-29 Superfortress, as well as early jets like the F-84. That worked fine for a while, until the first MiG-15 jet fighters appeared. UN losses were so heavy that the B-29s switched from daylight raids over Pyongyang to night bombing.

The United States responded with its premier fighter jet—the F-86 Sabre. MiG and Sabre both owed a lot to captured Nazi research into jet propulsion (see the resemblance), but there were significant differences between the aircraft. The lighter MiG could out-climb and out-accelerate the Sabre, packed heavier armament and could fly a few thousand feet higher, which allowed it to bounce the Americans from above. But the Sabre could dive faster, was more stable to fly and had a radar gunsight.

Some of the American pilots were World War II aces. Against poorly trained North Korean and Chinese pilots, they racked up kills. But when the Soviets sent their World War II aces to Korea, the Americans found themselves in a real fight (and put the lie to German-inspired stereotypes that Russian pilots were inept).

Korea began the era of Cold War limited wars, where politics and fear of starting World War III limited the scope of combat. But that didn't make the dogfights over Mig Alley any less intense. The United States claimed a 10:1 kill ratio in favor of the F-86, though recent research suggests the true number was less than 2:1.

Operation Linebacker II:

Goliath's armada of 200 giant B-52 bombers had been designed to drop nuclear bombs to incinerate Moscow. Except that in Christmas 1972, the bombers were hitting Hanoi, capital of a small Southeast Asian nation that had been a mere French colony twenty years before. Operation Linebacker II was supposed to pound North Vietnam into signing a peace agreement that would end its attempt to conquer South Vietnam.

It should have been a cakewalk for crews trained to penetrate the Soviet Union's extensive air-defense system. Unlike a strike mission on Leningrad, the bombers would have extensive fighter, air-defense suppression, tanker and rescue support. But the Americans faced a tightly integrated air-defense system of Soviet-supplied anti-aircraft missiles, anti-aircraft guns and Mig interceptors—a tested system that had withstood American bombing for seven years.

One problem was that Goliath hobbled himself. Political restrictions constrained the missions. Strategic Air Command, which prided itself on extreme oversight of America's nuclear force, insisted on micromanaging bombing missions, including requiring all the B-52s to attack from the same direction, altitude and exit route. Pilots were even forbidden to take evasion to evade SAMs. The North Vietnamese gunners couldn't have asked for a better Christmas present if Curtis LeMay himself had come down Ho Chi Minh's chimney in a Santa suit.

Fifteen B-52s were shot down, mostly on the early and badly planned raids, as well as another dozen tactical aircraft. There are reports that some bomber crews were ready to mutiny rather than continue the same stupid tactics. Losses eventually dropped when SAC took a step back to allow local commanders to stagger attack routes to confuse the defenders, and used more jammers to neutralize SAMs (not to mention the North Vietnamese were running out of missiles).