Patron Saint Of:
Sailors who were crossing a sea while on business for Gertrude's monastery were caught in a ferocious storm and threatened by a large sea animal who they feared would capsize their boat. After one of the sailors prayed to God for mercy because they were doing business for Gertrude's ministry work, they said that the storm miraculously stopped right away and the sea creature swam away from them.
Gertrude was born into a noble family who lived at King Dagobert's court in Belgium. Her father served as mayor of Dagobert's palace. When Gertrude was 10 years old, King Dagobert tried to arrange a marriage between her and the son of an Austrasion duke in order to form a political alliance, but Gertrude refused to marry him because she wanted to become a nun in the church instead, saying that she would only be married to Jesus Christ.
Gertrude did become a nun, and she worked with her mother to start a monastery at Nivelles, Belgium. Gertrude and her mother both served as co-leaders there. Gertrude helped build new churches and hospitals, and she took care of travelers and local people in need (such as widows and orphans). She also spent lots of time in prayer vigils.
Since Gertrude was known for offering hospitality (to people as well as animals), she was kind to the cats that hung around her monastery, offering them food and affection. Gertrude is also associated with cats because she often prayed for the souls of people in purgatory, and artists of the time symbolized those souls as mice, which cats like to chase. So Gertrude came to be linked with both cats and mice, and now serves as the patron saint of cats.