A rare 400-year-old Gospel has been found in a Bulgarian church, preserved in secret down the centuries and containing notes on major events in Bulgarian history.

According to Archaeology in Bulgaria, the book, printed in 1644 in Bulgarian Cyrillic, was discovered on the death of Fr Penyu Tsvyatkov Penev, a priest at the church of St. Elijah the Prophet in the town of Voynezha. It is believed to have been passed down from priest to priest in the church for generations.

It is now in the Sofia National Museum of History. A statement from the museum said: "The book...is richly decorated with dyes and ornate initials, the font is large and solemn, the pages are framed with decorative elements. Apparently, the book was actively used for religious services and reading: many of the pages have traces of candle wax, and the lower edges where the pages are turned are stained and worn out."

As well as its decoration, however, the book is significant because of the notes it contains. In 1644 Bulgaria was under Ottoman rule. Among the notes are an entry dealing with a rebellion in 1835 in which northern Bulgarians rose against the Turks in rebellion. "Velcho's Plot" is a little-known episode in the Bulgarian struggle for liberation, says Archaeology in Bulgaria.

Other books and artefacts have been found hidden in churches and other old buildings. However, museum director Bozhidar Dimitrov said that in 40 years he had only found one book older than this hidden in a church.