Wicca has no central authority figure. Its traditional core beliefs, principles, and practices were originally outlined in the 1940s and 1950s by Gerald Gardner and an early High Priestess, Doreen Valiente. The early practices were disseminated through published books and in secret written and oral teachings passed along to their initiates. There are many variations on the core structure, and the religion grows and evolves over time. It is divided into a number of diverse lineages, sects and denominations, referred to as "traditions", each with its own organisational structure and level of centralisation. Due to its decentralized nature, there is some disagreement over what actually constitutes Wicca. Some traditions, collectively referred to as British Traditional Wicca, strictly follow the initiatory lineage of Gardner and consider the term "Wicca" to apply only to similar traditions, but not to newer, eclectic traditions.