The history of the Puritans can be traced back to the first Vestments Controversy in the reign of Edward VI, the formation of an identifiable Puritan movement in the 1560s and ends in a decline in the mid-18th century. It is a complex evolution, with the situation of the Puritans as a religious group in England changing almost decade by decade, as a consequence both of political shifts in their relationship to the state and the Church of England, and of changing views of Puritans, both clergy and laity. It can not easily summarised, since the dramatic events of the 1640s, sometimes called the Puritan Revolution, have complex roots, any more than the term "Puritan" can be given a useful and precise definition outside the particular historical context.