|Weaponry:||Sword of El|
Jax-Ur was a Kryptonian warlord during the Age of Wars.
Although the underlying factors that led to the Age of Wars had been building for years, Jax-Ur began the conflict with the invasion of the province of Nol-Yan that became the catalyst, and played a large role in keeping the fighting ongoing.
At some point of time, Jax-Ur established contact and trade with the Dheronians for their deposits of Raonite ore which are to be use for building Nova Javelins. Jax-Ur was eventually defeated in combat by Von-El, who cut out one of Jax-Ur's eye with the Sword of El. He was then ultimately arrested and exiled by the Twelve Wise Ones, and Krypton's cycle of war was broken.
In posterity, Jax-Ur was arguably considered the most reviled figure in Kryptonian history. Due to his notoriety, the term "Ur-Thrall" was referred to those who sided with Jax-Ur were said to be in thrall of him during the Age of Wars and became contemptuously synonymous with any Kryptonian acting in an uncivilized, barbarous, or warmongering fashion.
Consequently, Jax-Ur's trade with the Dheronians abruptly ended in which it created a economic disaster for the Dheronians that built an animosity between the Dheronians and Kryptonians, and inadvertently led to Krypton's destruction.
In DC Comics, Jax-Ur is a mad Kryptonian scientist who was banished to the Phantom Zone for his reckless and dangerous experiments, the last of which accidentally destroyed one of Krypton's moons, taking five hundred Kryptonian lives with it.