Marta is the main ‘port’ of Lake Bolsena and the area has been inhabited since pre-Roman times, as can be deduced from the discovery of graves in the town of Carnossa and Monte Leano. According to some scholars, its origins date back to the Phoenician period, from which hence the name of Marath.
In the sixth century AD, on the island of Martana the queen of the Ostrogoths, Amalasunta, was imprisoned and was killed at the hands of killers of her cousin Theodatus, who wanted to usurp power. In 1070 Pope Gregory VII found the bones of Santa Cristina, martyr of Bolsena.
The fortress was built by Pope Urban IV in the second half of the thirteenth century. According to the legend for the construction the remains of the Bisenzio were used. Today it is reduced to a few ruins, including the featured Clock Tower.
The story of Martha follows that of other Tuscia centers where some families alternated in power: the Bisenzio, the Orsini and the De Vico
In the sixteenth century the Farnese took charge of the Duchy of Castro, that Paul III Farnese had created for his son, and remained there until 1649 when Castro was destroyed and the duchy ended.
Towards the end of the eighteenth century in two short periods it was given in perpetual lease to the Marquis Della Fargna and the Polish Prince Stannislao Poniatowsky. Then he returned it to the Church and it followed its fate until the unification of Italy.