In ancient times, customary daily prayers were recited by heart, or a reader prayed aloud and the congregation responded to the blessings with “Amen”. There were no books containing the texts of the prayers. It was said, “The writers of blessings are like those who burn the Torah.” (Tosef. To Shab. 13:4). Writing down the text of blessings was considered forbidden.
However, after the Talmud as written, this idea was abandoned and people started to write prayer books. At first it was only permitted to use these new prayer books in Babylon on the Day of Atonement and other fast days, but later they came into general use.
Rabbi Amram ben Sheshna haGaon, the leader of the Talmudic Academy at Sura in Babylon, wrote the first Siddur in about 875CE. This Siddur was written especially for scholars. One of his successors, the famous Saadia Gaon, compiled a siddur for general use in 882-942CE.
At first there was no difference between the siddur (containing the regular prayers for the whole year) and the Machzor (the prayer book written according to the cycle of the year). Early on they were used indiscriminately. As time went on, however, there were additions made for special days (e.g.: the piyutim, which were added to the Machzor). Then the Ashkenazi custom of differentiating between the siddur (prayers only) and Machzor (prayers plus piyutim) came into being.
During the Middle Ages prayer books grew longer and longer, as Jews wanted to spend more time in prayer. New supplications, new penitential prayers, new poems on a variety of religious themes were all added. No rabbinical synod met to vote on which prayers should or should not be included. Individuals made content selections in a very informal manner.
It was not only the desire to pray that stimulated the expansion of the siddur, but also the fact that Jews could read. Literacy was extremely high amongst Jews at a time when most men in Europe could not even sign their own names. The serious concern of the learned J ews for women’s spiritual needs led to the production of a special translation intended for women. (Whereas boys were routinely taught Hebrew so that they could understand prayers and religious texts, girls were not at that time.)
Before 1446 all prayer books were written by hand. With handwriting came minor changes and errors, which confused the original text. The first printed prayer books appeared in the early 1500s, but since their type was set by hand, the errors multiplied. A German Jewish scholar, Seligman Baer, printed a definitive siddur in 1886, after he had carefully traced all sources and compared all manuscript versions available. This text is used in all recently published traditional Siddurim.
As some Jews in the 16th century lost the skills in Hebrew that their ancestors had possessed, translations became necessary. Unfortunately this trend has continued and the number and variety of siddur translations has increased as Hebrew knowledge decreases around the Jewish world.