Rabbi Yaakov Chaim Sofer, better known as the Kaf Hachaim (the name of the monumental halachic work which he authored), was born in Baghdad in 1870. In his youth he studied Torah under the Sephardic greats of the times, such as the Ben Ish Chai.
In the beginning of the 20th century Rabbi Yaakov Chaim emigrated to the Land of Israel, and settled in Jerusalem. There he became renowned as a great kabbalist as well as a recognized halachic authority. He authored an eight-volume book on Jewish law, with a special focus on Jewish law and customs from a mystical viewpoint.
He passed away on the 9th of Sivan in Jerusalem and was buried on the Mount of Olives.
It is the custom of many communities (and such is the Chabad custom) to continue the weekly study of a chapter Ethics of the Fathers ("Avot"), one chapter each Shabbat afternoon, through through the summer, until the Shabbat before Rosh Hashanahn (the first six-week cycle is completed on the six Shabbatot between Passover and Shavuot). This Shabbat, being the first Shabbat after Shavuot, we study Chapter One.