Exomna
Exomna was a Goddess worshiped by the Batavi people in modern day Southern Netherlands. Unfortunately we do not know anything about this Goddess since we only have one altar stone on which she is mentioned.
The Batavi were originally part of the Chatti tribe but for some unknown reason, internal conflict most likely, a part of the Chatti tribe broke off and migrated to what is now the Southern Netherlands. They settled there around 100-50BC. We know that the Batavi were Germanic in origin because of the Chatti but it seems that they started to worship Celtic influenced deities as well, perhaps a consequence of living so close to Celtic territories.
The chief God of the Batavi was Hercules Magusanus, about whom I have written a post before. Hercules Magusanus was the Latanized version of the thundergod Donar/Thor. Several inscriptions to this God, including statues have been found in Batavi territory. The God Wodan/Odin was worshipped by the Batavi as well under the name of Mercurius Friausius. Archeologists however found several altar stones with inscriptions of completely unknown deities which still leave us puzzled until this day.
This photo of an altar stone, which dates back to around 150-300AD is the only inscription that we have of the unknown Goddess Exomna. The inscription reads: "Aunius Vitalis has fulfilled his vow to the goddess Exomna, gladly and with good reason."
The name Exomna is Celtic so she might have been one of the many unknown native southern Dutch Goddesses worshiped by earlier tribes like the Eburones who were destroyed by Julius Caesar. The Batavi people settled in former Eburones territory. What is also interesting is that the location where this stone was found, also is the site where a little statue of the God Mercurius has been found.
It is now theorized that the location where this stone was found, Alem, the Netherlands, was the site of a temple dedicated to multiple Gods. The Batavi might have simply adopted the native Exomna when they settled here around 100-50BC. Maybe future finds will uncover more about this mysterious ancient Dutch Goddess since we still have no clue what her exact role was in the old Dutch pantheon of Gods.