Barcelona was founded by the Romans who set up a colony called Barcino at the end of the 1st century BC. The colony had some thousand inhabitants and was bounded by a defensive wall, the remains of which can still be seen in the old town. 

For over 200 years, Barcelona was under Muslim rule, and, following the Christian reconquest, it became a county of the Carolingian Empire and one of the main residences of the court of the Crown of Aragon. The fruitful medieval period established Barcelona's position as the economic and political centre of the Western Mediterranean. The city’s Gothic Quarter bears witness to the splendor enjoyed by the city from the 13th to the 15th centuries.
From the 15th to 18th centuries Barcelona entered a period of decline, while it struggled to maintain its economic and political independence.

Climate in Barcelona

The climate in Barcelona is typically Mediterranean. Summers are hot and humid, winters mild, and most of the rainfall is in spring and autumn.

Its average annual temperature is 20 °C (68 °F) during the day and 11 °C (52 °F) at night.

In the coldest month – January, typically the temperature ranges from 8 to 17 °C (46 to 63 °F) during the day, 2 to 10 °C (36 to 50 °F) at night.

In the warmest month – August, the typically temperature ranges from 25 to 31 °C (77 to 88 °F) during the day, about 20 °C (68 °F) at night.

Generally – "summer's" / "holiday" season lasts about six months, from May to October. Two months – April and November – are transitional, sometimes temperature exceeds 20 °C (68 °F), with average temperature of 17–18 °C (63–64 °F) during the day and 8–9 °C (46–48 °F) at night.

December, January and February are the coldest months, with average temperatures around 14 °C (57 °F) during the day and 5 °C (41 °F) at night. Large fluctuations in temperature are rare, particularly in summer months. Sunshine duration is 2,524 hours per year, from 138 (average 4.5 hours of sunshine at day) in December to 310 (average 10 hours of sunshine at day) in July.