Coat of Arms
Shield Azure-Argent with an armillary sphere Or. Naval coronet lined in Gules. Under the shield, a banderole wavy Argent with the motto “N.R.P. SINES” in dark capital letters, elzevir font.
Patron
It was in the XIII century that Sines acquired autonomous administration. On November 24th, 1362, D. Pedro I grants a letter elevating Sines to town, interested in its coast defensive role, stating as a condition the construction of a castle. It is on this date that the Municipal holiday is celebrated.
It was in this county that Vasco da Gama was born, a land of great history and enormous patrimonial value. The stable settlement in the heart of Sines, area of the castle, starts with the Romans. One of the hypotheses of the origin of Sines´ toponymy comes from the Latin word “sinus” which means bay or bosom, the configuration seen from the top of Mount Chãos. In the Roman period, Sines becomes the center of fish salting production, a role that is progressively replaced by the Ilha do Pessegueiro.
The life of the modern age county continues marked by maritime roles and also by the Ilha do Pessegueiro. At the end of the XVI century there was a project by Filipe I of Portugal for the construction of a great artificial island port, which was not built, but whose initial project construction is still visible today. By the end of the XVIII century, Jacinto Bandeira, member of the merchant bourgeoisie establishes the Porto Covo´s settlement, again, with the assumption of a future construction of a great fishing port and one commerce port.
The XX century is marked by the municipal´s restoration and by the election of the first Mayor, Manuel Farelo.
The development of Sines´s industry as its initial point here and the successive increase of the population was such that on June 12th, 1997, Sines was elevated to city.
Nowadays, the city of Sines is still marked by a commercial growth phase of its port. 
