The birth of Islam in the 7th century was a transformative event with a lasting global impact. This book provides a comprehensive estimate of the world Muslim population from the inception of Islam to the end of the 21st century. The world is organized into continents, regions, and present-day countries, with centennial estimates from 600 to 2100 and decennial data from 1790 onward. For each unit, total population, Muslim population, and corresponding percentages are presented. The data show a steady rise in the global Muslim share: from about 3% in 700 to 16% by 1700, followed by fluctuations around the 18th and 19th centuries. Since 1950, the proportion has grown consistently, reaching 26% in 2020. Growth is expected to slow, with projections of 32% by 2050 and 40% by 2100. The book serves as a reference for studies involving Muslim populations, including economics, migration, policy, and social development.