Glendronach was built in 1826 by James Allardice, and rebuilt following a fire in 1852 by an individual named Walter Scott (although not the one you might be thinking of). It eventually passed into the hands of perhaps Scotland's greatest distilling dynasty, the Grant's of Glenfiddich. Charles, the youngest son of William Grant procured the then-silent distillery from the government in 1920, and it remained in the family until they sold it to Wm. Teacher 40 years later. The Grant's and Teacher's were early champions of the single malt category, and distillery bottlings of Glendronach were produced for most of the 20th century until it was mothballed by Allied Distillers in 1996. The distillery was revived in 2002, and has since become one of the strongest single malt brands in the world.
The Original 12 year old expression was first released in the 1980s, and matured in sherry oak and plain oak. They were available alongside the popular 100% Sherry Casks 12 year old for several years, before both were replaced by the bourbon and sherry matured Glendronach Traditional in 1991, launched as part of the short-lived Caledonian Malts range from Allied Distillers.
When the distillery was re-opened in 2002, The Original 12 year old was brought back, but was later reimagined as this fully sherry matured expression in 2005, produced from a combination of Pedro Ximenez and Oloroso sherry casks.