‘The Church Eye’ or the Big Constitution is a book gathering all of the most important church services, structured by hours and dates. It appeared in the Russian church in the 14th century while copies (replicas) of it were made up to the 17th century. After the 17th century, Church Eyes were printed in print shops. The Big Constitution from the museum is one of the latest printed versionsthe of the 17th century. It was finalized at the times of Patriarch Joseph I and published in 1641 at Patriarch Joseph.

‘The Church Eye’ contains daily, weekly and festive services, which were celebrated at fixed calendar dates. The book consists of rules for celebrating holy days, guidelines for performing church rituals and detailed instructions. The Big Constitution solved the question of the right order of reading or singing prayers from the Prayer Book, Horologion or the Book of Eight Tones. With the help of ‘The Church Eye’ the paschal cycle (days for celebrating the Great Easter at different years) could be easily counted of.

During divine services several church books could be used at the same time. The Big Constitution noted how to keep the right order of prayers in that case. Most of the book was devoted to these rules, however, the Constitution also contained disciplinary instructions: how to keep the fast by lay people and monks, how to pray in churches, monastic cells and before feasts.

The first edition of ‘The Church Eye’ was printed in 1610 at the times of Patriarch Hermogenes. It was one of a few books published at the Time of Troubles. In 1633, the new Patriarch Philaret ordered to burn the whole edition of the Constitution in front of the people in Moscow as heresy. At present, the main book for determining the order of divine services is the Big Constitution of 1641.

The binding of the ‘Church Eye’ is made of two wooden plates covered by leather. It is very well-preserved. The leather is ornamented with lining – a pattern pressed on the surface of the book cover. A special pattern mould was pressed to the smooth surface of the binding until a print could be seen. The Constitution was locked by metal clips ornamented with floral design. The book was renovated in the 19th century.