BELMONTE, Portugal — After 500 years of being Roman Catholic in public and keeping their Jewish traditions alive in private, the Jews of Belmonte are cautiously leaving their self-made ghetto of secrecy.

The community of about 300 in this hilltop village in the heart of Portugal dates from the late 15th Century.

It was then that thousands of Sephardic Jews chose conversion to Catholicism as an alternative to expulsion, torture or death at the hands of the Inquisition.

The Jews became known as Marranos, a word believed to derive from the old Spanish for pig and still an insult in the Belmonte community, and defied their Roman Catholic persecutors by practicing their religion clandestinely.

Portuguese monarchs, eager for tax revenue and Jewish talent, had protected the thriving Sephardic community in their own country and offered shelter to Jews persecuted in neighboring Spain. Sepharad is the Hebrew name for the area now comprising Spain and Portugal.

After 1496, however, King Manuel I forced about 80,000 Jews to convert to Catholicism in order to seal a royal alliance with Spain's powerful rulers, Ferdinand and Isabella. Four years earlier, Isabella had signed an edict expelling from Spain all Jews who refused to convert.

Manuel's successor, John III, decided to hunt out heretics and hidden Jews. Portuguese inquisitors ordered the first burning of a heretic in 1543, and the last occurred in 1765.

Even 169 years after Portugal formally abolished the Inquisition, Belmonte's Jews find it hard to be open about their religion.

They still attend Mass with their Catholic neighbors at the village church where, for so many generations, they have been baptized, married and buried under marble tombstones.

"They've lived on the outside like Christians. . . . On the inside, in their houses, they were not Christians, they were Jews, and they have transmitted this from father to son," said Colette Avital, Israel's ambassador to Portugal.

Jewish leaders still hesitate to tell outsiders their story.

Licinda Melo, a village official, said: "Jewish community leaders have asked me to tell tourists, even tourists from Israel, that there are no more Jews living here, that it's just a legend."

The reluctance is reflected in suspicions that remain between Jews and the 3,000 or so Catholics in Belmonte. The village is in one of Europe's poorest regions, the mountains of Lower Beira province, and many families live on the equivalent of less than $200 a month.