Russia is the biggest supplier of natural gas to Europe, which depends on the former for nearly 40% of its natural gas requirements. Russia is followed by Norway, which supplies about 22% of Europe’s gas needs; Algeria and Azerbaijan supply under 20% and 10% respectively.

https://www.thehindu.com/news/international/explained-how-dependent-is-europe-on-russia-for-its-energy-needs/article65064946.ece