Original: The Invitation to William was a letter sent by seven notable Englishmen, later named the Immortal Seven, to William III, Prince of Orange, received by him on 30 June 1688 (Julian calendar, 10 July Gregorian calendar).
Simplified: They were later named the Immortal Seven. They sent this letter to William III, Prince of Orange, received by him on 30 June 1688 (Julian calendar, 10 July Gregorian calendar).