Peri Ez Hayyim, a forerunner of Hebrew periodical literature, was issued by the well-known yeshivah Ez Hayyim founded in 1616. In the 18th century the yeshivah became the largest and most important Torah center not only of Sephardi Jewry but of Ashkenazi Jewry as well. Accordingly, halakhic queries addressed to the yeshivah's outstanding talmudists reflect the entire spectrum of Jewish life in the 17th and 18th centuries and all aspects of halakhah. Decisions or advice were requested on such matter as inheritance laws, civil claims, social conflicts, shipping merchandise, piracy, the slave trade, the value of coinage and its fluctuations, Jewish housing difficulties in Holland, agunot, and marriages between those of greatly differing ages. Most of the decisions are dated and signed by the rabbis who gave them. The responsa indicate that, in the main, Dutch Jewry lived completely within the religious tradition, even though some of the inquirers, particularly among the women, no longer knew Hebrew. Halakhic inquiries came predominantly from Holland and its colonies, with some coming from the Mediterranean littoral and elsewhere. There are letters that reveal their writers to have been Marranos, whose problems are also clarified in these responsa. Although almost all the responsa are on halakhic matters, occasionally information about and reactions to other things are also recorded. Thus, there are praises for the art of printing and for science, accounts of the history of the Spanish Jews in Amsterdam, and the Hebrew poet David Franco-Mendes' history of the yeshivah Ez Hayyim and of Peri Ez-Hayyim. Only a few copies of each responsa were published and as a result a complete set is no longer extant. Of the 952 responsa, 948 have been preserved and these are housed in different libraries throughout the world (e.g., the Ets Hayyim library in Amsterdam, the Rosenthal collection of the Amsterdam University Library, the National Library in Jerusalem, and the library of J.L. Maimon in Jerusalem).