Strangling the Serpents

'The Infant Hercules Strangling the Serpents' by Sir Joshua Reynolds

It was commissioned by Catherine the Great in 1785 and she trusted Reynolds to chose any subject matter he liked. 

He said I have chosen the theme of the superhuman strength of the infant Hercules, for the subject admits of an analogy – distant perhaps – with the mature and well-known power of the Russian Empire' 

Here is the commissioner as painted by V Borovikovskiy a bit later in 1794. 

She had lived with the baby Hercules painting for about 9 years. She is pointing at The Chesme Column. On the top is an eagle (symbol of Russia) and it is trampling a crescent moon (symbol of Turkey). 

Perhaps her love of the Chesme Column inspired Reynolds to create another scene symbolically representing Russian strength. 

Eagles fight with snakes, and at first glance the flick of the crescent moon looks like a snakes tail. 

Have a look -

The symbolism of the Eagles strength is as universal. Here is a Byzantine mosaic from The Grand Palace in Istanbul with an eagle and snake in mid battle.