Another example is Jan van Eyck’s Arnolfini Double Portrait, 1434. This painting serves to verify that this man and woman actually did marry.

Arnolfini Double Portrait (van Eyck, 1434)

Giovanni Arnolfini was living in Flanders far from his native Italy.
When it came time for him to marry, a matchmaker found a nice Italian girl living with her parents in Paris. She traveled up to meet him, and they got married in his home, as pictured here. Not only is the groom taking the loyal oath of matrimony, but also everything else in the painting documents the episode. Below, the dog represents marital fidelity (dogs are loyal to their masters); Giovanni is barefooted (his wooden sandals are at the bottom left) as he treads on the ground of holy matrimony; the window shutters are open and citrus fruit is on the sill referencing the profession of the man (import/export); the bed is on the bride’s side of the painting as her role is to produce children; the chandelier has one lit candle (the presence of God at the wedding); and the mirror and rosary beads on the back wall evidence their Catholic faith. However, above the mirror, Jan van Eyck wrote his name to verify the actuality of the event, and within the reflection in the mirror, figures are standing where we are, again suggesting that the couple married with the appropriate witnesses. In effect, this painting serves as marriage certificate.