In truth - the martial arts started with Cain killing Abel, in the Mesopotamia, in the dawn of mankind. Man since then has continued developing new ways to defeat their enemies. There were martial arts in the Middle East, in Babylon, in Egypt, and in China. The oldest book known in Chinese history is known as Kojiki, or the "record of ancient matters". Even in this book, we find reference to fighting skills, and the martial arts.
So, really, the beginning of martial arts goes back to the dawn of civilization. The term that we reference as "Bujitsu", or "the Arts of War" that is commonly translated into English as "martial arts", we can caption in the following flow chart. This at least will help people to understand the idea of the martial arts that they study.
China is the cradle of the martial arts. Since its origin thousands of years ago, people have been developing martial skills alongside their healing counterparts, generally referred to as "Kung Fu" ("human effort" or "human ability"), and later, Chu'an Fa ("Chinese hand" or "Chinese boxing"). China was the birth place of what we refer to today as the "martial arts". In its original design, the Kung Fu systems of China were guarded secret systems to ensure that the family heritage and safety would remain intact. These were the arts of the assassins. These arts today are still well guarded, and their secrets are largely still vaulted within the families, and their circles.
Japan's Bujitsu etching is found within the Emperor's protectors, known as the Samurai. Japan owes their martial heritage to China though their trading lines. The Samurai developed their version of swordsmanship (Kenjitsu), and unarmed combat known as Jujitsu ("gentle art"). The Chinese grappling art of Chin'na ("Seizing hands") gave root to their combat Jujitsu techniques. People were born into the Samurai class, and their fighting arts remained inside the closed doors of their family. However, when Japan unified in 1868, the Samurai class was abolished, and martial arts became open to the public to learn. The military killing arts (Bujitsu) were replaced with the more civilized personal and academic arts known as "Budo", or, "the way of the warrior". This lead the way for the development of the arts ending with the word "do" (way /philosophy) rather than ending in "jitsu" (referencing "fighting arts"). This lead most notably to Jigaro Kano's Judo ('gentle way"), Morei Usheba's Aikido ("meeting energy way"), and from Kenjitsu, Kendo ("way of the sword").
Consistent with the rest of the history of martial arts, Okinawa, the birth place of Karate, owes its development to China. The first Karate system known as "Te" (hand) entered Okinawa through the trading posts of Southern China, notably in the area of the Ryukyu Islands.
There are many misconceptions about the art of Karate today, and it has been fragmented, splintered, and bickered about through the decades. Karate as an art is a new art - not ancient - and not martial. Karate was developed less than 100 years ago, which actually makes it younger than baseball! Karate, although a Japanese term, is a Chinese art. There is no founder of Karate, and no exact system. It has been added to, and taken away from, through the opinions of consecutive teachers. The development of "Karate" as we have it today has been footnoted to an individual named Gichin Funakoshi (1868 - 1957). He is recognized as the father of Japanese Karate. In 1936 he coined the phrase "Karate-do" ("the way of the empty hand"). In his mind, there were no "forms" or "systems" of karate. There was just "Karate". One system. One philosophy.