A brief history of apparitions
The earliest known claim was from St. James the Greater who saw the Virgin Mary while he was in preaching on the banks of the Ebro River in Saragossa, Spain in 40 A.D. Today, apparition reports occur more frequently. Some scholars estimate the total number of apparition claims throughout history to be approximately 2,500 (with about 500 of those coming in the 20th century alone). According to the Dictionary of Apparitions of the Virgin Mary, throughout history 308 apparitions are attributed to Saints or Blesseds. They are generally unofficially recognized by Church authorities (or at least the orders and congregations that they have founded or belonged to). Only 7 Popes throughout history have witnessed Marian apparitions.
The Catholic Church has been very cautious to approve purported miraclous events. In fact, in the 20th Century, of the hundreds of public claims, there have been only 9 with episcopal approval (4 of those with Vatican approval) and a handful of others that have not received official approval but have been approved for faith expression at the site. A total of 22 apparitions throughout history have been investigated and have received episcopal approval. Additionally, there have been four Egyptian apparitions approved by the Coptic Orthodox Church in the last 50 years. The list of rejected claims continues to grow.