Secret chamber uncovered during cathedral renovation. An ornate sarcophagus was inside

While preparing to build a crypt underneath the Świdnica Cathedral in Poland, workers discovered the space was occupied. A tomb — dating back over 300 years — was already there.

A secret chamber was uncovered under the church, which is perched along a riverbank in southwest Poland, and an ornately decorated coffin was found inside, according to an Aug. 7 news release from the diocese.

A shield and assorted weaponry were painted onto the tin coffin, which sat atop a pile of stones inside the small, dark room, photos show.

Though it was hidden, church officials were able to identify whom the coffin belonged to thanks to extensive German inventories made in 1935.

The sarcophagus held the remains of Count Georg von Schlick, an Austrian military commander who lived during the 17th century.

Schlick fought during the 30 Years’ War, a bloody conflict spanning much of Europe.

He died in 1640 while besieged by enemies in Jelenia Góra, a city about 40 miles west of Świdnica.

The discovery of the coffin and the hidden chamber came as a surprise to Bishop Marek Mendyk, according to the release, though he believes the cathedral dating to the 13th century likely holds even more secrets.

Construction began on the cathedral in 1330 and was funded in part by the city’s aristocracy, according to the church website. Over the ensuing centuries, war and fire damaged the structure, prompting extensive repair work and additions.

The church was officially designated as a cathedral in 2004, and in 2017, the Polish president gave it the title “Monument of History.”

Świdnica is about 260 miles southwest of Warsaw.

Google Translate was used to translate a news release from the Diocese of Świdnica and a description of the cathedral.