The epitaph found on the tombstone from the monastery of Umm Leisun is written in the Georgian Asomt’avruli (uncial) script. It mentions Iohane, Bishop of Purtavi. Based on paleographic considerations, the inscription should be placed in the rank of the early Georgian inscriptions, i.e., the end of the fifth or, more likely, the first half of the sixth century CE. This inscription attests that the Umm Leisun Monastery was a Georgian cloister.