Cathedral of St. James Senior (Karija, Korija[2][3]) was a mediaval Roman Catholic church in what was once Krbava (near nowadays Udbina).

The information about consecration of Krbava Cathedral to St. James Senior was found by bishop Mile Bogović, while searching the Vatican Archives in 1997.

The diocese of Krbava which was centered around the cathedral of St. James Senior was first founded in 1185 on provincial Church Council in Split.

In 1460, due to ever increasing Ottoman akinji raids, the diocese moved its seat to Modruš, which was then owned by the Frankopan family.

In spite of the damage caused to the site, this later helped Croatian archeologists to begin with the research, in the aftermath of the Operation Storm.

[4] The 36 x 12 m layout of the one-nave Krbava cathedral fits central-European sacral architecture pattern and shows that the site also housed a local bishop.