The Castle of Trani is one of the most important and, despite the suffered mutations, one of the best legible among the castels erected from the emperor Federico II of Swabia to guardianship of his favorite Kingdom of Sicily, inherited by his mother, the princess Norman Constanza of Altavilla.
The foundation of the castel, on a rocky more low in comparison to the firm earth and probably isolated since the origin, it involved the destruction of a modest outpost of look-out, a small tower of referable watch to the centuries X - XI, recovered under the actual entry.
Important datum on the coast pugliese of the castels system of Federico II, in the XIII century the most modern of Europe, rises not too far from the famous cathedral, strategically situated to the center of a roadstead, whose low backdrops would always be revealed a good natural defense, both from the fury of the waves and from possible attacks on the northern front.
On model of the cruciform castles of Earth Saint, it had simple and functional quadrangular plant, strengthened to the vertexes from four square towers of peer height.
The castel, with the sequence of the dynasties, first to the Angioinis, then to the Aragonese ones, it was always, up to our days, of government ownership, except a brief period (1385-1419), when it was assigned to the captain Alberico da Barbiano, thanks to the services made to Charles III of Durazzo in struggle for the succession with Luigi D'Angiò.
Preserving unchanged the strategic value of the position, in the XVI century, with the advent of the fire weapons, the castle was adjusted to the new defensive techniques, answering to the diffused demand of re-fortification of the Mediterranean coasts, threatened by the Turkish advance. The operation involved the increase of the southern front, less favorite from the nature and overlooking the open country and the realization of two bastions to the opposite edges of southwest (to point of lance) and northeast (to square plant), assuring the fire hedgetop coverage of the whole perimeter of the fortitude.
The Castle uninterruptedly covered its role of military garrison, to exception of the years 1586-1677, when it was center of the Sacred Regal Hearing of the province of Barri, until, in the XIX century, was turned to provincial central jail, destination stopped only in 1974.
Restored by the Superintendence for the Environmental, Architectural, Artistic and Historical heritage of Puglia, from 1979, it has been open to the public June 5 th 1998.