The SZD-56 Diana is a 15 metre Class glider originally designed by Bogumił Bereś at PZL-Bielsko. However, PZL Bielsko went bankrupt before it could be put into serial production.
The rights to the design were taken over by a new entity, Diana Sailplanes, which developed the design further into the Diana 2. The Diana 2 first flew on 12 January 2005.

After two years of development, in 2018 a new design using a fuselage from Czech manufacturer KKB and a wing from Diana Sailplanes was introduced for the 18 metre Class called the Diana 3.