The patron saint of Sesto San Giovanni is Saint John the Baptist, celebrated on 24 June in the church dedicated to him.
Around the turn of the 19th and 20th centuries the town saw strong industrial growth, as Milanese entrepreneurs moved their plants there: among the leading companies were Breda, Ercole Marelli, Magneti Marelli, Falck, Campari and Garelli, which pushed the population up to 14,000 inhabitants as early as 1911, and earned the town, for the sheer extent of its heavy industrial facilities, the 19th-century nickname «Little Manchester». After the Second World War, owing to the massive presence of Communist-leaning workers and its leading role in the Resistance, the town became known as the «Stalingrad of Italy», a stronghold of the left until 2017. The industrial crisis of the 1990s led to the closure of all the historic factories, the last of which, Falck, in 1996: the areas once occupied by the plants are today undergoing intense urban redevelopment, which has also involved internationally renowned architects such as Renzo Piano.
