Maritime republics
Pisa
### Pisa

[upright\|left\|thumb\|The Pisan cross](/wiki/File:Flag_of_the_Republic_of_Pisa.svg "Flag of the Republic of Pisa.svg")
[thumb\|upright\|left\|The [Pisa Baptistery](/wiki/Pisa_Baptistery "Pisa Baptistery"), built in the 14th century](/wiki/File:Pise-Baptistere.jpg "Pise-Baptistere.jpg")
[thumb\|The [Leaning Tower](/wiki/Leaning_Tower_of_Pisa "Leaning Tower of Pisa") and the [Pisa Cathedral](/wiki/Pisa_Cathedral "Pisa Cathedral"), built in the 12th century](/wiki/File:CampoDeiMiracoli2.JPG "CampoDeiMiracoli2.JPG")
The Republic of Pisa was born in the 11th century. In this historical period, Pisa intensified its trade in the Mediterranean Sea, allied itself with the [Kingdom of Sicily](/wiki/Kingdom_of_Sicily "Kingdom of Sicily")'s nascent power, and clashed several times with the Saracen ships, defeating them in [Reggio Calabria](/wiki/Reggio_Calabria "Reggio Calabria") (1005\), in [Bona](/wiki/Annaba "Annaba") (1034\), in [Palermo](/wiki/Palermo "Palermo") (1064\), and in [Mahdia](/wiki/Mahdia "Mahdia") (1087\).

Originally, Pisa was governed by a Viscount, whose power was limited by the Bishop. In the 11th century, entering into the struggles between these two powers, the city, governed by a Council of Elders, acquired a *de facto* autonomy, which was then made official by [Henry IV](/wiki/Henry_IV%2C_Holy_Roman_Emperor "Henry IV, Holy Roman Emperor") in 1081\.

In 1016, an alliance of Pisa and Genoa defeated the Saracens, conquered Corsica and the [Sardinian judicates](/wiki/Sardinian_medieval_kingdoms "Sardinian medieval kingdoms") of [Cagliari](/wiki/Judicate_of_Cagliari "Judicate of Cagliari") and [Gallura](/wiki/Judicate_of_Gallura "Judicate of Gallura"), and acquired control of the [Tyrrhenian Sea](/wiki/Tyrrhenian_Sea "Tyrrhenian Sea"); a century later they took the [Balearic Islands](/wiki/Balearic_Islands "Balearic Islands"). At the same time, Pisa's economic and political power increased considerably with the commercial rights acquired with the [Crusades](/wiki/Crusades "Crusades"), thanks to which it was able to establish numerous warehouses in the Holy Land. Pisa was always the most fervent supporter of the [Ghibelline](/wiki/Guelphs_and_Ghibellines "Guelphs and Ghibellines") cause, thus opposing the Guelphs Genoa, Noli, [Lucca](/wiki/Lucca "Lucca") and [Florence](/wiki/Florence "Florence"): its currency, the aquiline, always bore the name of the [emperor](/wiki/Holy_Roman_Emperor "Holy Roman Emperor").

Pisa reached the peak of its splendor between the 12th and 13th centuries, when its ships controlled the western Mediterranean and was able to express [Pisan Romanesque](/wiki/Pisan_Romanesque "Pisan Romanesque") in the field of art, a mixture of Western, Eastern, Islamic and classical elements.

Pisa's rivalry with Genoa sharpened in the 13th century and led to the naval [Battle of Meloria (1284\)](/wiki/Battle_of_Meloria_%281284%29 "Battle of Meloria (1284)"), which marked the beginning of Pisan decline; Pisa ceded Corsica to Genoa in 1299, and in 1324, the [Battle of Lucocisterna](/wiki/Battle_of_Lucocisterna "Battle of Lucocisterna") saw Sardinia ceded to [Aragon](/wiki/Aragon "Aragon"). Unlike Genoa, Pisa needed to control a hinterland, which saw the rival cities of Lucca and Florence nearby: this subtracted forces from their navy and brought the republic to ruin.

In the fourteenth century, Pisa passed from a municipality to a [lordship](/wiki/Signoria "Signoria"), maintaining its independence and essentially the dominion of the [Tuscan](/wiki/Tuscany "Tuscany") coast, and made peace with Genoa. However, in 1406, the city was besieged by the Milanese, Florentines, Genoese and French and annexed to the [Republic of Florence](/wiki/Republic_of_Florence "Republic of Florence"). During Florence's crisis in the [Italian Wars](/wiki/Italian_Wars "Italian Wars"), Pisa revolted against [Piero the Unfortunate](/wiki/Piero_the_Unfortunate "Piero the Unfortunate") and in 1494 reconstituted itself as an autonomous republic, restoring its own currency and magistracy. However, after 16 years of serious war, Florence managed to reconquer it definitively in 1509\.

The ancient [Porto Pisano](/wiki/Porto_Pisano "Porto Pisano"), now filled in by the [Arno](/wiki/Arno "Arno") floods, was located north of the current city of Livorno. The life of [Fibonacci](/wiki/Fibonacci "Fibonacci"), a mathematician from Pisa, well expresses the profitable relationship between commerce, navigation and culture typical of the maritime republics; he reworked and disseminated Arab scientific knowledge in Europe, including ten\-digit numbering, and the use of zero.

[thumb\|800px\|upright\=3\.6\|center\|Maximum expansion of Pisa in the Mediterranean Sea](/wiki/File:Massima_espansione_di_Pisa.png "Massima espansione di Pisa.png")


What event led to Pisa's annexation by the Republic of Florence in 1406?