Born as a son of Yi Seong-gye, a rising Goryeo general, and Lady Han of the Cheongju Han clan. He grew up amid late-Goryeo turmoil, when court factions, Mongol legacies, and regional militaries competed for control.

When Yi Seong-gye turned back from Wihwado Island instead of attacking Ming territory, Bang-won aligned with his father's decisive break from hardline war policy. The retreat accelerated the collapse of the Goryeo court and elevated the Yi faction in Kaesong.

After Yi Seong-gye founded the Joseon dynasty, Bang-won emerged as a core architect of the new royal house and its security. He navigated uneasy cooperation with reformist officials who sought to limit royal power through bureaucratic institutions.

As Joseon shifted its political center away from old Goryeo power networks, Bang-won backed the consolidation of authority around Hanyang. The relocation reduced the influence of entrenched Kaesong elites and refocused governance on new institutions and palace guards.

Bang-won led a violent coup against Jeong Do-jeon and allied officials, who promoted a weaker monarchy and supported a younger heir. The purge shattered reformist dominance and marked Joseon's founding as a contest between bureaucratic governance and royal supremacy.

In the aftermath of the coup, the young Crown Prince Yi Bang-seok, backed by Jeong Do-jeon, was removed amid lethal palace politics. The event deepened the family's fractures and demonstrated that succession would be settled by force as much as by ritual.

Traumatized by bloodshed, King Taejo abdicated and retreated from court life, leaving the throne to Bang-won's brother, King Jeongjong. Bang-won remained the decisive power behind the scenes, controlling military leverage and key appointments in the capital.

Conflict with Prince Yi Bang-gan escalated into open fighting as factions armed themselves in the capital region. Bang-won's victory removed the last major princely challenger and convinced King Jeongjong that only abdication could prevent further civil war.

King Jeongjong abdicated, and Bang-won became King Taejong, formalizing the power he had already secured through coercion and alliance-building. He framed his rule as restoring order after succession chaos, while tightening control over ministers and princes.

Taejong pressed officials and aristocratic families to submit to royal oversight, limiting private armies and factional patronage. By reshaping appointments and enforcing discipline, he aimed to make the throne—not ministerial coalitions—the ultimate arbiter of policy.

He expanded palace security forces and reduced the capacity of nobles to maintain independent armed followings. This shift helped prevent another princes' war and made the capital's coercive power reliably answer to the monarch and central ministries.

Taejong pushed stronger household registration and taxation practices to increase state revenue and administrative visibility. By tightening records on land and labor obligations, he reduced local manipulation and improved the court's ability to fund defense and governance.

He rebalanced top offices so that high ministers advised but could not dominate the throne, learning from the Jeong Do-jeon crisis. The restructuring strengthened direct royal command over appointments, military affairs, and major policy deliberations at court.

Taejong pursued a mix of punitive expeditions and frontier administration to contain raids and secure Joseon's northern borders. His policies sought to stabilize border counties and integrate local military command under centralized oversight rather than regional strongmen.

He invested in institutions that would outlast his personal authority, emphasizing predictable procedures and reliable revenue. The result was a sturdier platform for long-term statecraft, preparing the ground for a more scholarly and cultural reign under his heir.

Taejong stepped down and elevated his son Sejong, managing the transition to avoid the succession violence that had scarred his own rise. Even in retirement, he remained an intimidating elder statesman whose authority shaped early Sejong-era politics.

He died after two decades of centralization that transformed Joseon from a fragile new regime into a durable dynastic state. Later generations debated his bloodstained path to power, yet acknowledged his institutional legacy behind Sejong's celebrated achievements.