Construction of the campanile of the Cathedral of Pisa (now known as the Leaning Tower of Pisa) begins; it will take two centuries to complete.
Pisa Cathedral (Italian: Cattedrale Metropolitana Primaziale di Santa Maria Assunta; Duomo di Pisa) is a medieval Roman Catholic cathedral dedicated to the Assumption of the Virgin Mary, in the Piazza dei Miracoli in Pisa, Italy, the oldest of the three structures in the plaza followed by the Pisa Baptistry and the Campanile known as the Leaning Tower of Pisa. The cathedral is a notable example of Romanesque architecture, in particular the style known as Pisan Romanesque. Consecrated in 1118, it is the seat of the Archbishop of Pisa. Construction began in 1063 and was completed in 1092. Additional enlargements and a new facade were built in the 12th century and the roof was replaced after damage from a fire in 1595.
A bell tower is a tower that contains one or more bells, or that is designed to hold bells even if it has none. Such a tower commonly serves as part of a Christian church, and will contain church bells, but there are also many secular bell towers, often part of a municipal building, an educational establishment, or a tower built specifically to house a carillon. Church bell towers often incorporate clocks, and secular towers usually do, as a public service.
The term campanile (, also US: , Italian: [kampaˈniːle]), deriving from the Italian campanile, which in turn derives from campana, meaning "bell", is synonymous with bell tower; though in English usage campanile tends to be used to refer to a free standing bell tower. A bell tower may also in some traditions be called a belfry, though this term may also refer specifically to the substructure that houses the bells and the ringers rather than the complete tower.
The tallest free-standing bell tower in the world, 113.2 metres (371 ft) high, is the Mortegliano Bell Tower, in the Friuli Venezia Giulia region, Italy.