Which Spartan king became closely associated with Xenophon?

The Spartan king who became closely associated with the Greek historian Xenophon was Agesilaus II.1

Following his service with the mercenary army known as the Ten Thousand, Xenophon became deeply involved with senior Spartan figures, most notably developing a close relationship with Agesilaus II after 396 BCE. Xenophon’s admiration for the king is evident in his work titled Agesilaus, where he presents the monarch as a "completely good man" whose virtues are explored through narrative and analysis. Xenophon’s alignment with Sparta was so significant that he fought for the city at the Battle of Coronea in 394 BCE, and he later lived in exile at Scillus, a site provided by the Spartans.12