In the spring of 2013, historian Donald Kagan delivered a rallying cry for the study of Western civilization — an speech that fans and critics alike deemed a fitting conclusion to Kagan’s celebrated, if controversial, Yale career.

But a year into his retirement, Kagan has opted to return to the Yale seminar table. Now a professor emeritus of classics and history, he will once again offer a fall history seminar on “Thucydides and the Peloponnesian War.”

Kagan, who won a National Humanities Medal in 2002, is most famous for his four-volume account of the Peloponnesian War. As Dean of Yale College from 1989 to 1992, he faced protests over a $20-million gift from Lee Bass for a course in Western civilization. Bass eventually dropped the gift, but Kagan maintained a reputation as a champion of Western civilization and, increasingly, as a leading neoconservative. During the Bush era, Kagan’s name became associated with his advocacy for increased defense spending and broad American military power.

After the first round of history seminar pre-registration, Kagan’s seminar was one of two fully enrolled seminars. The other was Gilbert Joseph’s “Revolutionary Change and Cold War in Latin America.”

The last time Kagan’s seminar was offered, student evaluations expressed regret that it would not be offered again.

“I’m sorry there’s no more opportunities to take a course from him,” one student wrote, calling the course “the most effectively taught at Yale” and Kagan “the nicest professor at Yale.”