San Sebastián is the capital of the Spanish province of Gipuzkoa. As it belongs to the Autonomous Community of the Basque Country, the full Basque name of the city is Donostia-San Sebastián. It is located around twenty kilometers west of the French border in the arc of the Bay of Biscay.

The first mention of the name San Sebastián dates back to the early 11th century in the description of a local monastery. Until the rise of Bilbao in the 14th century, San Sebastián was the central port of the province. After a major fire in 1489, which destroyed the entire settlement, the settlement and the port were rebuilt as a base for the Cantabrian navy, which had to fight French, Dutch and British armadas again and again until the end of the 19th century.

San Sebastián was granted city rights in 1662 by King Philip IV. After the conquest in 1719, the city was occupied by a French garrison until it was returned to Spain in the peace treaty of The Hague in 1721. During the Napoleonic era, the city was first occupied by the French and then almost completely burnt down again during the liberation.

In 1863, Queen Isabella II ordered the city walls to be demolished in order to enlarge the city. As the summer residence of the Spanish kings, San Sebastián subsequently became socially popular.

During the First World War, the city developed into the cosmopolitan center of Europe, with prominent personalities such as Mata Hari, Leon Trotsky and Maurice Ravel frequenting the then world-famous casino. During the dictatorship until 1975, San Sebastián served as Franco's summer residence.

Since the democratization, the city has been trying to mediate in the Basques' quest for autonomy. San Sebastián was chosen as the European Capital of Culture in 2016 and is therefore currently benefiting from enormous investment in infrastructure, art and society.

On June 15, 1981, the twinning of the two state capitals was signed in Wiesbaden City Hall. At the festive reception, a delegation from San Sebastián signed the city's Golden Book.