Rabbi Ya'aqob ibn Habib was born in Zamora, Spain in 1460. He was one of the greatest rabbis and Talmudist of his time and the head of the Yeshiba in the city of Salamanca, Castilla (Central Spain). When the Jews were expelled from Spain in 1492 he and his family left to Portugal. But in 1496 the Jews were given the choice to convert to Catholicism or to abandon Portugal. Rabbi Ya'aqob left Portugal and settled in Salonica (today Thessaloniki, Greece) where he founded the new congregation of "Megoreshe Castilla", the exiled from Castilla (Since those days Salonica became one of the most important and influential cities for Sephardic Jewry for centuries. Up until recent times the economic presence of the Jews was so important that the Salonica Port was closed on Shabbat. In 1943 more than 60,000 Jews --95% of the Jews of Salonica-- were deported and killed in concentration camps. Today approximately 1,500 Jews live in Salonica).
In Salonica Rabbi Ya'qaob Ibn Habib he found a generous patron, Don Yehuda Benveniste, who placed his rich library at his disposal. That library contained many books on the Talmud from the most distinguished commentators. There Rabbi Ya'aqob Ibn Habib wrote the famous book 'en ya'qaob, a collection of all the non-Halakhic discussions, Midrashim and ethical teachings of the rabbis of the Talmud, with the commentaries and remarks of rabbi Ibn habib (pirush hamehabber). 'en ya'aqob was first published in Salonica in 1516, a few months after Rabbi Ya'qaob had passed away. Rabbi Ya'aqob wrote only on two of the six sections of the Talmud (zeraim and mo'ed) but the book was completed by his son, Rabbi Levy ibn Habib (the famous רלב"ח) .
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In those days, many gentiles and conversos were attacking the Talmud with ridiculous accusations. In 1546 the book was republished in Venezia. But in 1555 the local Inquisition declared the Talmud as a book of heresy. And the 'en ya'aqob was burned in the public square together with copies of the Talmd Babli and Yerushalmi. After ten years the ban against the book expired. And 'en ya'aqob was again published in 1565, but under a different name: 'en Israel.
'en Ya'aqob or 'en Israel became a very popular book among Sephardim and Ashkenazim. There are dozens of different editions and hundreds of commentaries, including contemporary commentaries (see for example this).
The 'en ya'aqob had a very special place among the Tora curriculum of Sephardic Jews. Up until recent times 'en ya'aqob was a textbook for young students (elementary school). It was studied as an indispensable introduction to the Talmud. Before navigating the complex Talmudic legal hermeneutics, the young student would learn from 'en ya'aqob the style, the narrative and especially the language of the Talmud.
See here one of the oldest editions of 'en ya'aqob, Venezia 1625.