Medieval history may seem a bit arcane to most undergraduates, but this spring they'll have the opportunity to take courses with a prominent Oxford historian of the subject.

Karl J. Leyser, a visiting professor of history who retired from All Souls College in Oxford last year, says he was invited to Harvard in order to fill a gap in the History Department's curriculum.

Leyser will be teaching two courses at Harvard this spring, History 1160, "The Medieval Empire: 900-1250" and History 2270, "Medieval History." "I was specially invited here to teach these courses because apparently they had been unavailable before," he says.

And no matter how many students show up for the two courses Leyser plans to teach this spring, the British historian says he plans to continue his "lifetime's work" of making the esoterica of German medieval history accessible to history students.

Leyser, who has written two books and numerous papers on medieval history, says he has spent the bulk of his 40-year teaching career concentrating on German history and such historical figures as Gregory VII and Henry IV.

The scholar says that he became interested in his esoteric field when he began teaching at Oxford in 1948. According to Leyser, someone suggested to him that medieval Germany was an interesting, and largely unexplored, field.

"Medievalists are generally interested in England and France," said Leyser, "and not much attention was given to central Europe. It's my lifetime's work."

Leyser's scholarly credits include two books--Rule and Conflict in an Early Medieval Society and Medieval Germany and its Neighbors--which were published both in England and the United States.

In addition, Leyser wrote the section on medieval German history for the years 900 through 1250 for the most recent edition of the Encyclopedia Brittanica.

In the course of his lengthy academic career, Leyser has spent time in the United States as a visiting professor at the University of California at Berkeley. His stint at Harvard this spring was arranged before his retirement last year from Oxford, so the scholar decided to prolong his stay in academia for at least another semester.

A World War II veteran who fought in the bloody Battle of the Bulge, Leyser was a friend and colleague of the famous Oxford theologian and writer C.S. Lewis.