A Moleben is a service of intercession, or service of supplication in honor of Jesus Christ, the Mother of God, a Feast, or a particular saint or martyr.
Molebens are traditionally served by a priest, but may also be done as a reader's service, omitting or replacing those portions normally chanted by the priest. It is the custom to celebrate a Moleben service only in honor of a glorified saint, and when possible the service is done in front of an icon of the person or feast to whom the Moleben is celebrated.
The Moleben to the Blessed Virgin Mary has its roots in a very ancient prayer called the Paraklys and is a shortened version of the Matins, complete with a gospel reading. It originated in Western Ukraine at the beginning of the 20th century and was composed by Father Meletius Lonchyna. It has evolved into a much loved service that traditionally is used every Wednesday throughout the year and during the month of May.