The shulhan 'arukh is known to be "the Code of Jewish Law", and "the most authoritative legal code of Judaism".
Here is what most people don't know about the shulhan 'arukh.
A SUMMARY OF BET YOSEF
The shulhan 'arukh, written by rabbi Yosef Caro (1488-1575) is NOT an independent book. It is a summary of the monumental book written previously by rabbi Yosef Caro himself, the Bet Yosef . In the Bet Yosef (it took him 32 years to write this book) rabbi Caro examines and analyses Jewish Law from the Talmud through the interpretation and commentaries of the most important Rabbinical authorities up to his own time. In the theshulhan 'arukh rabbi Caro wrote the halakhic conclusions of the Bet Yosef. Rabbi Yosef Caro wrote the shulhan 'arukh for the sake of Tora scholars who need to have an accessible brief halakhic guide. He also states in his introduction that he writes this short book (in terms of its text, the shulhan 'arukh is perhaps 3% of the Bet Yosef) to be memorized by the young students. He also divided the shulhan 'arukh in 30 sections so it can be reviewed once a month. All this implies that before reading the shulhan 'arukh one must read the Bet Yosef. The shulhan 'arukh cannot be properly understood, let alone, used as a source of law, without studying first the Bet Yosef.
FOR SEPHARDIM and ASHKENAZIM
The Bet Yosef/shulhan 'arukh was written explicitly as an attempt to bridge the gaps between Sephardim and Ashkenazim. In his introduction to the Bet Yosef, Rabbi Caro sates that in his days the Tora became like multiple Torot. He identified mainly three traditions. The Spanish communities who followed Maimonides, the Franco-German tradition who followed the Rosh, and the North african communities who followed the Rif. Rabbi Caro based his Bet Yosef on the book who follows the Rosh (The "TUR", written by the Rosh's son), and as a rule, to establish the final Halakha he followed the opinion of the majority of these three Rabbis. In this way, he hoped, Sephardim and Ashkenazim, would compromise some of their previous customs and all Jews would follow and adopt one single set of Laws.
(To be continued...)