The windmill was built in 1816, and subsequently leased to was leased to the Ashby Family, and used the wind to make flour until 1862, then was converted to other types of power and remained in operation until the 1930s.
It was subsequently restored and in the 1960s passed into public ownership and is now a grade II* listed structure, preserved by Lambeth Council and the Friends of Windmill Gardens. Today's reopening ceremony, which follows extensive refurbishments, sees live music, a parade, a fancy dress competition, and the first tours of the refurbished windmill. It all kicks off at 2pm.
For more information, see http://www.brixtonwindmill.org/