[Edited by Ellopos from Wikipedia articles.]
The original Hebrew of this book is lost and the most important surviving version is the Greek translation contained in the Septuagint. The book is held as canonical scripture by the Catholic, Orthodox, and Oriental Orthodox churches (except for the Orthodox Tewahedo), but not by Anglican and Protestant denominations. In modern-day Judaism, the book is often considered to be of great historical interest, but has no official religious status.
The setting of the book is about a century and a half after the conquest of Judea by the Greeks under Alexander the Great, after Alexander’s empire has been divided so that Judea was part of the Greek Seleucid Empire. It tells how the Greek ruler Antiochus IV Epiphanes attempted to suppress the practice of basic Jewish law, resulting in the Maccabean Revolt (a Jewish revolt against Seleucid rule). The book covers the whole of the revolt, from 175 to 134 BC, highlighting how the salvation of the Jewish people in this crisis came through Mattathias’ family, particularly his sons, Judas Maccabeus, Jonathan Apphus, and Simon Thassi, and Simon’s son, John Hyrcanus. The doctrine expressed in the book reflects traditional Jewish teaching, without later doctrines found, for example, in 2 Maccabees. The First Book of Maccabees also gives a list of Jewish colonies scattered elsewhere through the Mediterranean at the time.
In the first chapter, Alexander the Great conquers the territory of Judea, only to be eventually succeeded by the Seleucid Antiochus IV Epiphanes. After successfully invading the Ptolemaic Kingdom of Egypt, Antiochus IV captures Jerusalem and removes the sacred objects from the Temple in Jerusalem, slaughtering many Jews. He then imposes a tax and establishes a fortress in Jerusalem.