The Book of Kells: How the 1,200-year-old illustrated manuscript at Trinity College is taking in over €20m

The revenues for the 12 months to September last also include income from the Old Library Shop and guided tours, and compare with just €16.7m for the prior year – an increase of €3.5m.

A TCD spokeswoman said revenues last year increased as 900,000 people visited the Book of Kells exhibition, compared with 740,000 a year earlier.

TCD students last month barricaded the rooms where the Book of Kells is kept, in protest at TCD’s ties with Israel. A five-day protest camp by college students ended after Trinity agreed to the students’ demands.

The spokeswoman was unable to quantify the financial impairment caused by the protesting students.

The Book of Kells dates from about 800AD and has been on display in the Old Library in TCD from the mid-19th century. The priceless national treasure contains the four Gospels in Latin and was lavishly illustrated by monks.

In January of this year, TCD unveiled the new Book of Kells Experience, which involves visitors first viewing the book in the Old Library, before entering the Long Room. Visitors then continue their journey in a new pavilion in the New Square, where a sound and light show awaits.

Tickets for the 90-minute experience include both the Old Library and pavilion and are €25, with concessions for seniors, students and children.

This is a 28pc increase on the €19.50 adult charge that was in place for the 45-minute experience for the Book of Kells and Old Library.

The spokeswoman said that TCD is reworking elements of its long-term project to conserve and redevelop its Old Library, “considering the inflationary pressures that have affected all construction projects nationally”.

She said the proposal to issue a tender for design services will be considered at the university board meeting later this month.

“Until this stage is finalised we cannot confirm the final budget or completion date.”

Last year, TCD enjoyed revenues of €513.8m.