1717 (MDCCXVII) was a common year starting on Friday of the Gregorian calendar and a common year starting on Tuesday of the Julian calendar, the 1717th year of the Common Era (CE) and Anno Domini (AD) designations, the 717th year of the 2nd millennium, the 17th year of the 18th century, and the 8th year of the 1710s decade. As of the start of 1717, the Gregorian calendar was 11 days ahead of the Julian calendar, which remained in localized use until 1923.
The War of the Quadruple Alliance (1718–1720) was caused by Spanish attempts to recover territories in Italy ceded in the 1713 Peace of Utrecht. Largely focused on Sicily, it included minor engagements in North America and Northern Europe as well as the Spanish-backed Jacobite rising of 1719 in Scotland.
The 1720 Treaty of The Hague was signed on 17 February 1720 between Spain and the Quadruple Alliance, established by the 1718 Treaty of London. Its members included Britain, France, the Dutch Republic and Austria.