Answer:
Napoleon's forces and a coalition of other European countries
Step-by-step explanation:
To put a little bit of context,
At that time, Napoleon planned to attack the Russian empire and abolish the influence of the church and the kings within its government.
At that time, the Russian Monarch position themselves as the righteous and convinced their people that they are fighting on the behalf of God's will (to protect divine rights by king and church leadership). This is why they named their effort as 'The holy War'
To fight of Napoleon, the Russian monarch asked help from Austria and Prussia and joined their forces together. This is why 'Napoleon's forces and a coalition of other European countries ' would be the best answer.