Maharam of Rothenburg
Maharam was the foremost halachic decisor of his time, issuing thousands of responsa to rabbinic courts and colleagues throughout Europe. He was born around the year 1220 in Worms.
In 1286, as the legal status of Jews in Germany deteriorated, Maharam attempted to flee the country (as his disciple, R Asher b Yehiel, succeeded in doing shortly afterwards). He was caught and imprisoned, first at Ensisheim, and later, under better conditions, at Wasserburg. For years, while he languished in prison, he continued to teach his students and edited several of his earlier works (I once heard tell of a manuscript, in private hands, written by Maharam on pages from the prison log).
Maharam never left the prison alive. According to Maharshal (Yam shel Shelomo Gittin IV 6), he instructed his followers not to pay the ransom demanded for him because captives should not be redeemed for more than their worth (whether the story is true or not, that was in fact his position - see his responsa, ed. Berlin 1891, p. 205, no. 128; ed. Prague 1608, no. 78). He died on Iyyar 19th, 1293.
Even after his death the ransom was demanded. Eventually it was met, and Maharam was buried in Worms in 1307.