Ulithi is a large atoll in western Micronesia. The indigenous religion of Ulithi included a pantheon of sky gods, including a supreme god called I'aluep, the 'Big Spirit' or 'Great Spirit'. However, these gods were considered remote, and deified spirits of the dead were ritually more important. Most of the population of Ulithi converted to Roman Catholicism in the 1930s and 1940s.