The Essenes (in Modern but not in Ancient Hebrew: אִסִּיִים, Isiyim; Greek: Εσσήνοι, Εσσαίοι, or Οσσαίοι, Essḗnoi, Essaíoi, Ossaíoi) were a sect of Second Temple Judaism that flourished from the 2nd century BCE to the 1st century CE which some scholars claim seceded from the Zadokite priests. Being much fewer in number than the Pharisees and the Sadducees (the other two major sects at the time), the Essenes lived in various cities but congregated in communal life dedicated to asceticism, voluntary poverty, daily immersion, and abstinence from worldly pleasures, including (for some groups) celibacy. Many separate but related religious groups of that era shared similar mystic, eschatological, messianic, and ascetic beliefs. These groups are collectively referred to by various scholars as the "Essenes." Josephus records that Essenes existed in large numbers, and thousands lived throughout Roman Judæa.
The Essenes have gained fame in modern times as a result of the discovery of an extensive group of religious documents known as the Dead Sea Scrolls, which are commonly believed to be Essenes' library—although there is no proof that the Essenes wrote them. These documents include preserved multiple copies of the Hebrew Bible untouched from as early as 300 BCE until their discovery in 1946. Some scholars, however, dispute the notion that the Essenes wrote the Dead Sea Scrolls. Rachel Elior questions even the existence of the Essenes.
The first reference is by the Roman writer Pliny the Elder (died c. 79 CE) in his Natural History. Pliny relates in a few lines that the Essenes do not marry, possess no money, and had existed for thousands of generations. Unlike Philo, who did not mention any particular geographical location of the Essenes other than the whole land of Israel, Pliny places them in Ein Gedi, next to the Dead Sea.
A little later Josephus gave a detailed account of the Essenes in The Jewish War (c. 75 CE), with a shorter description in Antiquities of the Jews (c. 94 CE) and The Life of Flavius Josephus (c. 97 CE). Claiming first hand knowledge, he lists the Essenoi as one of the three sects of Jewish philosophy alongside the Pharisees and the Sadducees. He relates the same information concerning piety, celibacy, the absence of personal property and of money, the belief in communality and commitment to a strict observance of Sabbath. He further adds that the Essenes ritually immersed in water every morning, ate together after prayer, devoted themselves to charity and benevolence, forbade the expression of anger, studied the books of the elders, preserved secrets, and were very mindful of the names of the angels kept in their sacred writings.
Pliny, also a geographer and explorer, located them in the desert near the northwestern shore of the Dead Sea, where the Dead Sea Scrolls were discovered in the year 1947 by Muhammed edh-Dhib and Ahmed Mohammed, two Bedouin shepherds of the Ta'amireh tribe.