Throughout the 16th and 17th century, it was believed that women had less control of their sexuality than men. This lack of control made women weaker than their male counterparts. It was only through the quiet domesticity of marriage that lust could be tamed. Ironically, gender stereotypes are reversed today.
As discussed in a previous post, monkeys in Renaissance art often symbolized frivolity and gave a lighthearted feel to a painting. But monkeys also represented beastly desires. How does a queen control these desires? She must chain the monkey.
In the painting by Sir Anthony van Dyck, Henrietta Marie's monkey is safely chained to her dwarf, Sir Jeffrey Hudson. In this painting above of Catherine of Aragon, the queen is also not taking any chances with an unleashed monkey*. A chained monkey represented the subject’s absolute control over base desires. Clearly, neither queen is giving into that crazy monkey love.
* Actually it is a marmoset to those who know their monkeys
Sources: Edited by: Fudge, Erica, Renaissance Beasts, University of Illinois Press, 2004.