Korean History: A Concise Overview of Warlords, Empires, Colonists, and More

In 37 BC, Jumong, posthumously titled Dongmyeongseong, laid the foundation for Goguryeo, later centralized by King Taejo. Under King Sosurim's reign in 372, Goguryeo embraced Buddhism as its official religion, marking a significant cultural shift.

Goguryeo, also known as Goryeo or Kogury, played a pivotal role in shaping Korean history, ultimately lending its name to the modern-day nation.

Throughout the third and fourth centuries, Goguryeo faced territorial struggles with Chinese and Xianbei forces, experiencing both victories and setbacks. The Goguryeo–Wei War of 242 saw Goguryeo challenging Chinese authority, leading to reprisals that temporarily weakened its grip on certain regions. However, subsequent invasions by Goguryeo into Chinese territories, coupled with strategic advancements, solidified its dominance in the Korean peninsula.

In the 5th century, Goguryeo reached its zenith, emerging as a dominant force in East Asia under the leadership of Gwanggaeto the Great and his successor, Jangsu. Their conquests extended Goguryeo's influence into vast territories, including Manchuria, Inner Mongolia, and parts of Russia. This period marked a golden age for Goguryeo, characterized by unprecedented military prowess and territorial expansion.

Under Jangsu's rule, Goguryeo underwent significant political and economic development, further enhancing its institutional frameworks.

Goguryeo's militaristic ethos was exemplified in its conflicts with various Chinese dynasties, notably the Goguryeo–Sui War, where it defeated a formidable enemy, contributing to the downfall of the Sui dynasty.