The stage of the language known as “Middle Korean” lasted from the tenth century until the end of the sixteenth century. It began with the establishment of the Koryŏ dynasty in AD 918, when the new government moved the capital from Kyŏngju, in the southeast, to Kaegyŏng (later to be renamed Kaesŏng) in the middle of the peninsula. It nominally ended when the Japanese invaded Korea in 1592, and the resulting chaos disrupted the written record of the language.

Middle Korean can be most conveniently divided into two parts: Early Middle Korean and Late Middle Korean. The language of the Koryŏ period (918~1392) is considered to be Early Middle Korean, while the language of the first two hundred years of the Chosŏn period is taken to be Late Middle Korean. That division is not made to mark sweeping changes in the language. On the contrary, political and social developments point more toward linguistic stability than significant change between the Koryŏ and the Chosŏn. At the end of the Koryŏ, in 1392, the founders of the new, Chosŏn dynasty chose a place not very far away to build their capital. Unlike the move from Kyŏngju to Kaesŏng, the move from Kaesŏng to Seoul (then called Hanyang) took place over a relatively short distance and is usually thought to have had a minimal effect on the language. The regional base of the language did not change.

Where does the Korean language come from? This origin question is of ultimate interest to linguists, but it has also captured the imagination of the Korean lay public, who have tended to conflate the question with broader ones about their own ethnic origin. Linguistic nomenclature has added to the confusion. When specialists speak to the public about “family trees” and “related languages,” the non-specialist naturally thinks that the Korean language has relatives and a biological family like those people do. And when a people as homogeneous as Koreans are told that their language belongs to a family that includes Mongolian and Manchu, they envision their ancestors arriving in the cul-de-sac of the Korean peninsula as horse-riding warriors. It becomes a personal kind of romance.

In this way, linguistic theories presented in a simplistic way tend to overshadow complex ethnographic and archeological issues. But the linguistic question is no less complex, all the more so because, unlike archeological evidence, linguistic evidence cannot be dug from the ground. Artifacts have been extracted from the Korean earth that speak to the structure of earlier societies and cultures, but there is nothing of comparable age to be found in records of the language. To explore the history of the language at that time depth, far beyond what has been actually written down, linguists can only rely upon the comparison of Korean with other languages and hope to find one that has sprung from the same “original” source.

The story of Korean begins with the invention of the Korean alphabet. Ever since it was introduced in 1446, the Korean alphabet has been the source of precise and detailed information about the phonological and morphological structure of the language. In that year, some three years after an announcement of its creation had been made in the dynastic annals, the reigning monarch, King Sejong, promulgated a handbook introducing the new script and explaining its use, and from that point on Korean has been a language structurally accessible to future generations of linguists. Before the alphabet, there is virtually nothing in the way of quality documentation; with the alphabet, Korean structure is laid out for us to see. (The invention, how it happened, and what we know as a result, will be discussed in detail in Chapter 5.) Thus, lucid and precise written records of the Korean language go back slightly more than five and a half centuries.

That length of time may seem ancient by most standards, but it is not particularly long on the time scale of East Asian history, or even of Korean history. Chinese writing is thought to have begun around the seventeenth century BC; and it was certainly a fully developed writing system by the fourteenth century BC. That means histories were being written and literature composed almost two thousand years before the Korean alphabet was invented. That was of course in China.

In the world today, few nations are as homogeneous as Korea. There are no ethnic or linguistic minorities anywhere in its indigenous population. But the kinship-like bonds of this nation, together with its ties to the land itself, have fostered a monolithic view of the past. There is a tendency among Koreans to think of every artifact taken from Korea's soil as the handiwork of their forebears, every ancient tribe as ancestors, all prehistoric languages as forms of early Korean. However, in the remote past the Korean peninsula was a multicultural place.

Just when Korea became so homogeneous is not altogether clear, but certainly, there was a time when many diverse groups of people lived in that part of the world. Such was clearly the case around the beginning of the Christian era. In 108 BC, when Han Chinese forces first established commanderies on the peninsula, the region was already filled with local polities. In their interaction with these local groups, a process which had already been going on for centuries, the Chinese transcribed a scattering of names as best they could in phonograms. Some of the group names are thus preserved in Chinese historical annals; and from these records we know a little about where they lived and how they related to each other. But little institutional memory of the languages remains. For the most part, the vague records left about the peoples on the Korean peninsula provide room largely only for guesswork.

What is referred to here as “Early Modern Korean” extended from the beginning of the seventeenth century down to the end of the nineteenth century. It is the stage of the language represented in the texts written after the end of the Middle Korean period but before writing practices were updated and rationalized to reflect contemporary speech around the turn of the twentieth century. Early Modern Korean was, in that sense, a transition stage between Middle Korean and Contemporary Korean.

The Early Modern period began after the Japanese invasion of Korea in 1592. That invasion, followed by the seven, horrific years of the Imjin Wars, followed in turn by more years of widespread famine and disease, exacted a terrible price on Korean society. No books were published during that time, and when publication did resume around fifteen years later, Korean writing had changed. Gone were the diacritic dots used to mark tones; the triangle symbol used to write z had disappeared; consonant clusters and other kinds of spellings were confused and inconsistent; grammatical patterns and styles were noticeably altered. The differences in the textual records were so great, in fact, it was long believed that the wars with the Japanese had caused people to change the way they talked. Even today one sometimes hears it said that Hideyoshi's invasions caused Koreans to forget how to pronounce z's or to distinguish tones.

The story of Contemporary Korean begins with Korea's fitful emergence on the world stage in the late nineteenth century. The opening of Korean ports to outside powers brought sweeping political and social change to the country, and the pace and pressure only intensified over the next half-century. For the most part, the change was traumatic. The history of the Japanese colonial period, the partition of the country into north and south, and the culminating, internecine Korean War, was grim.

But the history of the language that played out against this backdrop was not altogether a story of misfortune. The reform of the language, particularly in how it was written, was very much at the center of what in Korea is called the “enlightenment period.” The stage for that movement was set in the early nineteenth century, when there developed out of the Sirhak (Practical Learning) tradition a body of scholarship, known as “enlightenment thought,” that argued for the opening of Korea to Western culture and technology. Then, when Korean ports were forcibly opened to foreign commerce with the Kanghwa Treaty of 1875, many of those Korean intellectuals looked toward constructing policies of reform and modernization. Thus began the “enlightenment period.”

At the top of the reformers' agenda was language. The creation of a modern state required a modern standard language for the proper functioning of society and government.