Berkeley Castle was built shortly after the Norman invasion by William FitzOsbern, the Bastard's guardian and counsellor; who fought alongside him at Hastings, and was subsequently made the 3rd Earl of Wessex, the only Norman to hold the title (unless the present incumbent counts). After his death in 1071, the original motte-and-bailey castle passed to one Roger de Berkeley, and subsequently to his son Roger de Berkeley and grandson Roger de Berkeley (the Normans apparently didn't quite understand how names work).
The present castle was constructed by Robert Fitzharding in 1153, 26 years after Edward II famously died when someone inserted a red-hot poker into his plop-socket (according to Holinshed, though his account of the murder has been disputed). In the 14th century, Dickie Pearce, the last court jester in England, died after falling from the Minstrel's Gallery, thus eliciting the biggest laugh of his career.
The castle was captured by the Parliamentarians during the English Civil War. In the 18th century, the 4th Earl of Berkeley planted a pine tree supposedly grown from a cutting taken at the Battle of Colluden.
More recently, Berkeley Castle has been used as a filming location in many historical and period dramas, such as The Other Boleyn Girl, Wolf Hall and Father Brown. It appeared in an episode of Who Do You Think You Are? when Courtney Cox traced her ancestry back to the aforementioned Edward II. It has given its name to two Royal Navy warships, and a Castle class steam locomotive owned by the GWR (and subsequently British Rail).
Today, the castle is a popular tourist attraction, open to the public between May and October and playing host to many events such as recitals of early English music, and Tudor-era re-enactments. The gardens feature many scented roses, a lily pond, and a butterfly house with 42 exotic species flying freely. Opening hours are 11am-5pm (10.30am for the gardens). Tickets are available online. The postcode, for satnav purposes is GL13 9PJ.