Here is a comprehensive summary of the Wikipedia article on Europe's population:
Europe's population currently exceeds 751 million people (as of 2018), constituting approximately 10% of the world's total, with Russia being its most populous country. The continent has experienced immense growth, from an estimated 1 million residents in 6500 BC to 741 million by 2015. However, Europe now faces significant demographic shifts characterized by low population growth, a high median age, and widespread "sub-replacement fertility," with the EU's average birth rate at 1.5 children per woman in 2020. Consequently, most European nations have older populations, holding nine of the top ten highest median ages globally in 2005. Despite these challenges, many Western European countries continue to grow, primarily due to substantial immigration and increased life expectancy. These demographic trends are rapidly transforming societies into multicultural entities, though Europe's share of the global population is projected to decline to around 7% by 2050.