The Venice Biennale started in 1895 at the Giardini di Castello. The gardens in the east of Venice were built between 1808 and 1812 during the Napoleonic era according to the master plan and architectural design by Giannantonio Selva. They are divided into two sections: the first is an elongated rectangle with a central promenade, whereas the second, larger section, has been the venue of the Art Exhibitions of the Biennale since 1895.
For the I Esposizione Internazionale d'Arte della Città di Venezia [1st International Art Exhibition of the City of Venice, opened on 30 April 1895], the organizers commissioned a Palazzo dell'Esposizione [Exhibition Palace], erected in 1894-1895. The building itself was designed by Venetian City Council's architect Enrico Trevisanato, and the neoclassical facade by the Venetian artist, Marius De Maria. Until 1905, the Biennale only occupied this Palazzo, where artists coming from different countries would gather and exhibit their works together, with no internal division.
Because of the great success achieved by its first editions, the Biennale encouraged foreign countries to build their own pavillion at the Giardini. In 1907, the first national pavilion that opened in the Giardini was the Belgian. Later on followed Hungary (1909), Germany (1909), Great Britain (1909), France (1912), and Russia (1914).
Alongside the Central Exhibition Pavilion, a total of 29 pavilions were built at different periods by nations participating in the Biennale, many of them designed by important architects.
(Summary compiled by Universes in Universe from the Biennale website and other sources.)