One of the oldest question in Klindom is the transition of Klingons between Star Trek, The Original Series and Star Trek, The Next Generation. Most everyone in Klindom knows that the it was due to a costume/make-up change through the years along with a difference in budgets between the shows.

This helps with the real life aspect but how does this explain the persona aspects? In Klindom, you will see Klingons dress as from the Original series like Kor, Koloth and Kang:

 

There are a number of "theories" concerning this issue...

1.) THE TWO-RACE THEORY
Concept: There are two racial groups on Qo'noS. One race has ridges, but the other does not.
Good: This is relatively simple, and it is a reasonable explanation.
Bad: Kor, Koloth, and Kang. They appeared in TOS, ridgless, but later appeared in DS9 with ridges. Also, if there are simply two races. It does little to explain Worf's line, "We do not discuss it with outsiders."

2.) THE GENETIC/PHYSICAL ALTERATION THEORY
Concept: The ridgeless Klingons were altered to appear more human.
They would serve on the Federation border to make the eventual conquest of humans easier.
Good: This one seems to cover most of the bases. It explains the ridges, and also explains Worf's unease with discussing the matter. Klingons consider hiding one's face (read: true nature) from an opponent, and if their ancestors did it, modern Klingons might feel shame. Also, it can explain KK&K; they were altered "back" into ridged Klingons when humans discovered the ruse.
Bad: ??????

3.) THE SUDDEN MUTATION THEORY
Concept: This theory assumes that Klingons spontaneously mutated around 2270, possibly as a result of a virus, or because of Tribbles(!).
Good: ??????
Bad: It fails to take into account Kahless, who had ridges in ancient times. It also doesn't explain how, in the matter of a few years, each House on Qo'noS managed to develop their own distinctive ridge pattern, carried on the line.

4.) THE NO-CHANGE THEORY
Concept: Klingons always looked that way.
Good: Simple.
Bad: It explains absolutely nothing. And I think that covers the biggies. I prefer number 2, as it is the theory that seems to best fit the facts, as far as I'm concerned. Here's my hypothetical story and history of the dilemma. I base it on personal theory, "The Final Reflection" by John M. Ford, and "Pawns and Symbols" by Majliss Larson. Take it or leave it, its just my opinion! If anyone can find some holes (other than "Klingons wouldn't do that" or "That's impossible"), I would appreciate hearing them, so I can alter my theory.

First contact between the Federation and the Klingons officially came in 2218. However, the Klingons had made numerous contacts with Federation and Earth vessels during the late 22nd Century; unfortunately for the Federation, few ever resulted in the humans returning alive.

However, they showed the Klingons that the Human race would be far more difficult to conquer than all before them, due to their resourcefulness. The Imperial administration at that time was fairly xenophobic, and believed that the best way to conquer these new enemies was to infiltrate them, gain their trust, and destroy them from within.
So began the Human Fusion project.

When the Klingon Empire began to make its initial plans regarding Human Fusions, they decided that they would be centered on a planet near the heart of the Empire known as Tahrn. On Tahrn, the Klingon scientists set up a massive genetic engineering lab in 2201, where millions of artificially fertilized zygotes were developed into baby Fusions. The engineers gave the Fusions an interesting feature. They would appear essentially human until middle age, at which point their features would mature into a much more Klingon appearance. It was thought that, should a Fusion survive until middle age, they would have certainly earned the honor to wear the ridges of a true Klingon warrior.

After a single year, there were 200,000,000 Fusion babies, in massive nurseries, cared for by 30,000 Imperial nursemaids. Once these initial babies had reached the Age of Ascension, they began their training as warriors for the Empire, under the military training of Imperial soldiers, and the nursemaids returned to the Homeworld.

During these developing years, a number of nearly brainwashing techniques were used on the Fusions. First, they were convinced to never disclose the existence of the Imperial race to any non-Klingon. Secondly, they were strongly urged to mate and reproduce as often as possible so as to increase the number of Fusions quickly. Lastly, they were made to believe that, while a level above humans and aliens, they were still inferior to the Imperial race itself.

Finally, in 2220, the first all-Fusion Klingon starship crews began to patrol the Federation borders. All contact with the Federation was made through specially trained Fusion diplomats. The Fusions obviously could not all be in space at once, so those that remained on Tahrn propagated the species. The average Fusion family had two parents and twelve children by 2226. By the late 2240s, both Tahrn and the Fusion colonized neighboring world of Peneli had full-fledged populations, and their own governmental system, ruled by their own Emperor. When visitors were brought into the Empire, such as Federation Ambassador Emmanuel Tagore, they were brought to Tahrn, which was code-named Klinzhai by the Empire. In this way, they were only exposed to Fusions, and could not belay the true nature of the race to the Federation.

Then, in 2271, the true nature of the Klingon race was revealed to Federation citizens with the interception of the "Amar Transmission." Federation scientists initially believed the Imperials to be genetically engineered "super-soldiers," a more powerful and aggressive breed than the others encountered before. However, communication with the Empire quickly revealed the true identity of the Imperial race.

By the mid 2280s, most of the initial Fusions were entering middle age. Famous warriors such as Kor, Koloth, and Kang managed to integrate seamlessly into Klingon society as Imperials with their newly-developed ridges. But then, the true Imperials were driven to anger at the shame of the Fusion deception launched by their forefathers. In one of the darkest moments of Klingon history, the Imperials slaughtered millions of Fusions on the three Fusion worlds, Tahrn, Peneli, Klairos. The planets themselves were nearly destroyed by orbital bombardment. Only those Fusions serving in the military escaped the holocaust, due solely to the fact that they had earned respect as honorable warriors. Even so, they and their children were altered on the genetic level to prevent further spreading of the Fusion impurity through the Imperial Klingon bloodline. However, since they had the courage to survive, they were heralded as great Klingons, and many attained the coveted rank of Dahar Master.

To this day, nearly all Klingons are ashamed of the dishonorable acts of their ancestors, and most simply refuse to discuss the matter with outsiders, lest they face open dishonor to their entire race. -McReynolds

This is my latest version of the Klingon Appearance explanation. It has its basis in the new book, "Star Trek Science Logs" by Andre Bormanis (Trek's science consultant). Further ideas are either my own, and a few date from a fanfic company, Orion Press. Anyway without further ado...

Originally, the Klingon race was much like humans. There was a diversity in skin and hair tones (though they tended towards the dark) as well as a variety of sub-cultures. Around the age of 35 or 40, Klingons began to develop the a series of bony ridges on their foreheads. The ridges were considered to be a sign of honor and wisdom, for in ancient times it was rare for a warrior to even reach the age of 50. By the time one was 50 years old, the ridges were fully developed.

In the early part of the 23rd Century, the leaders of the Empire experimented greatly with genetic engineering. Their ultimate goal was the development of a "super soldier," which basically amounted to a Warrior Caste. The Warriors were stronger and more cunning than their creators. Among their other distinctions was the unique feature of being born with their wisdom ridges already developed.

Unfortunately, in their effort to create a ruthless killing machine, the creators also endowed the Warriors with very little in the way of remorse, and a substantial sexual appetite. The result was genocide. Literally billions of natural Klingons were slaughtered, beginning in the late 2260s. Warriors interbred with the original race, producing mixed offspring. The Empire was plunged into chaos during the 2270s.

Finally, in the 2280s, the two groups of Klingons began to reconcile. Their one common ground was the worship of Kahless, and through his disciples, the Dahar Masters, the way of honor saved the Klingon race from extinction. However, the damage was done. Nearly all of the original race was dead, and most who survived were women carrying half-Warrior children. With their new code of honor firmly in place by 2300, the Warriors realized just how dishonorable they had been to attack not only their creators, but their own flesh and blood in a pointless conflict. As such, there exists a great deal of embarrassment and even denial regarding the subject well into the 2370s.

Note: Direct questions and comments to either alt.startrek.klingon or McReynolds whichever you prefer.

-McReynolds

Trekkan	Klingon	"Bear"