A century of Hangeul Day: From cultural independence to AI challenge

When King Sejong of the Joseon Dynasty (1392-1910) created “Hunminjeongeum,” the Korean alphabet now known as Hangeul, in 1443, it did not immediately replace the Chinese characters which Koreans had used for centuries.

For centuries afterward, it was largely shunned by the dynasty's aristocrats and intellectuals, who favored the use of Chinese characters. It wasn't widely popular among ordinary citizens either.

A major change came in 1894, when King Gojong declared Hangeul as the country’s official writing system. Three decades later, in December 1926, a group of Korean linguists and independence activists gathered and proclaimed Gagya Day — at the time, the name of Hangeul was not widely known and “gagya” was the starting sounds of people learning the alphabet.

That marked the beginning of what would later become Hangeul Day, which this year reaches its 100th anniversary. It was set on Sept. 29 based on the lunar calendar and was moved to the current Oct. 9 in 1940.

Historical legacy of Hangeul Day

Establishing Gagya Day a century ago was part of a cultural independence movement from Japan's colonial rule (1910-45), aimed at preserving the spirit of the nation, eradicating illiteracy and awakening national consciousness.

"It (Hangeul) helped break down the hierarchical status of written language and establish an independent Korean linguistic and cultural identity," Kim Ju-won, president of the Korea Language Society (KLS), told The Korea Times.

“Today, that same spirit extends beyond script preservation to establishing linguistic sovereignty in the digital and artificial intelligence (AI) era, spreading Hangeul globally and elevating our cultural standing.”

Reflecting on the history of Hangeul, it is impossible to discuss the Korean alphabet without mentioning linguist Ju Si-gyeong (1876-1914), founder of KLS.

“If King Sejong is the founder, inventor and creator of Hangeul, Ju can be considered the restorer, or an intermediary founder, who revived the script,” Kim said.

Ju is credited with giving Hangeul its current name, laying the foundations for modern Korean grammar and training disciples who later participated in compiling the Korean language dictionary and standardizing Korean grammar.

“Although King Gojong officially declared Hangeul the national alphabet in 1894 during the Joseon Dynasty, the nation soon faced foreign aggression. Ju emerged precisely when he was needed, passionately researching and educating the public about Hangeul while cultivating dedicated disciples who carried on his vital work,” Kim said.

Recently, Ju’s 1909 manuscript "Gukeo Munbeop" (Korean Grammar) and the original draft manuscripts of "Joseon-mal Keun Sajeon" (Dictionary of the Korean Language) were designated as National Treasures. The dictionary manuscripts have also been nominated for inclusion in the UNESCO Memory of the World Register.

Hangeul’s quality

One of Hangeul’s exceptional qualities lies in its simplicity.

The letters are modeled directly after the shapes of the human vocal organs, with consonants being categorized based on basic mouth and tongue shapes, representing a unique structural methodology unseen in global linguistic history. Developed more than 580 years ago, Hangeul represents a total synthesis of human linguistic knowledge created deliberately based on phonological principles.

With that feature, Kim said Hangeul made wide-ranging contributions to the Korean society over the past century.

"With its scientifically designed and accessible structure, Hangeul helped eradicate illiteracy in a relatively short period and democratize access to knowledge. It also played a crucial role in rapidly building the human resources needed for industrialization and in establishing democracy," Kim said, adding that such legacy has become "the foundation for globally popular K-culture and Korea's leadership in digital knowledge."

Describing Hangeul as a “scientific miracle,” Kim said its logical foundations allow it to bridge historical tradition with modern digital environments.

Securing data sovereignty in AI era

For Kim, preserving Hangeul in the 21st century is no longer simply a matter of protecting its written form. As language increasingly becomes data processed by AI, he sees another challenge emerging: securing Korean language data and ensuring that it remains accurately represented in AI systems.

“Securing data sovereignty by building large-scale, high-quality Korean language datasets is our most pressing challenge,” Kim said. “If we become overly dependent on global Big Tech models, we risk losing our technological independence. We must process and construct precise public and specialized corpora that accurately reflect Korea’s history, culture and academic knowledge to preserve our digital linguistic sovereignty.”

He acknowledged the scale of the challenge Korea faces in securing data sovereignty more broadly.

“There are 50 million of us generating data, and hundreds of millions, even billions, doing so in English,” he said. “The gap in scale is enormous.”

The issue, Kim said, is not simply technological but linguistic: Without sufficient high-quality Korean language data, the language could be underrepresented in the systems increasingly used to generate and process information.

Hangeul 'sharing'

Hangeul and the Korean language have seen their popularity rise globally over the past two decades, driven in part by the growing international fame of Korean music, dramas, films, games and webtoons.

The number of people studying Korean and taking Korean language proficiency tests is also on the rise around the world. According to the National Institute of International Education responsible for administrating the Test of Proficiency in Korean (TOPIK), the number of TOPIK applicants has nearly doubled from 223,000 in 2021 to 421,000 in 2025.

Kim is pleased to see these developments but does not like to describe them as the “globalization” of Hangeul.

“We deliberately avoid terms like the globalization of Hangeul, as that phrasing can carry imperialistic overtones, implying cultural superiority,” Kim said.

“Culture must be equal and mutually beneficial. Instead, we advocate for ‘Hangeul sharing.’ Foreigners study Hangeul out of affection for Korean culture. Our goal is to share the scientific value and creative principles behind Hangeul so global learners can connect deeply with Korean history.”

As to new terms, abbreviations and slang used by young generations, especially in the digital and AI era, Kim said they represent a "dynamic evolution of language." But he said they must rest on a solid foundation of accurate comprehension.

“Just as our predecessors established Gagya Day a century ago to achieve equality of knowledge through Hangeul, I hope future generations will understand its scientific principles and democratic values, taking pride in communicating confidently with the world.”