"Ma'oz Tzur" () is a Jewish liturgical poem or piyyut. It is written in Hebrew, and is sung on the holiday of Hanukkah, after lighting the festival lights. The hymn is named for its Hebrew incipit, which means "Strong Rock (of my Salvation)" and is a name or epithet for God in Judaism. It is thought to have been written sometime in the 13th century, although recent research suggests the 12th century. It was originally sung only at home, but has been used in the synagogue since the 19th century or earlier. In more recent years, of its six stanzas sometimes only the first stanza is sung (or the first and fifth). Time and author "Ma'oz Tzur Yeshuati" is commonly thought to have been written in the 13th century, during the Crusades. The first letters of the first five stanzas form an acrostic of the composer's name, Mordechai (the five Hebrew letters מרדכי). There are several hypotheses regarding his identity. He may have been the Mordecai ben Isaac ha-Levi who wrote the Sabbath table-hymn "Mah Yafit". Judging from the appeal in the closing verse, he may have been the Mordecai whose father-in-law was martyred at Mayence (now Mainz, Germany) in 1096 as part of the First Crusade. Avraham Fränkel (2014) suggests it was composed in Germany between 1160 and 1190. Some argue that the sixth stanza is an original part of the poem and was removed due to concerns of creating conflict with non-Jews, while others argue that it is a late addition. Content The hymn retells Jewish history in poetic form and celebrates deliverance from four ancient enemies, Pharaoh, Nebuchadnezzar, Haman and Antiochus. Like much medieval Jewish liturgical poetry, it is full of allusions to Biblical literature and rabbinic interpretation. Thus, malchut eglah denotes Egypt (Jeremiah 46:20); is Nebuchadnezzar; y’mini is Mordechai (Esther 2:5); y’vanim is Antiochus; shoshanim is the Jewish people (Shir HaShirim 2:2); b’nei vinah are the rabbinic sages; and shir refers to the Hallel psalms. A second acrostic is found in the first letters of the opening words of the final stanza, the acrostic contains the word hazak (, meaning "be strong"). The four middle stanzas refer to the salvations from the four persecutions of the Jewish people: The Exodus from Egypt, the end of the Babylonian captivity, escaping the persecution in Persia by Haman (the miracle of Purim according to the Book of Esther) and