Glauco was the lead ship of her class of two submarines ordered by the Portuguese government, but taken over and completed for the Regia Marina (Royal Italian Navy) during the 1930s.

She was scuttled by her own crew in mid-1941 after suffering heavy damage during a British naval attack.

[1] For surface running, the boats were powered by two 1,500-brake-horsepower (1,119 kW) diesel engines, each driving one propeller shaft.

They were also armed with two 100-millimeter (3.9 in) deck guns, one each fore and aft of the conning tower, for combat on the surface.

[2] Glauco was badly damaged by the British destroyer HMS Wishart and scuttled by her own crew on 27 June 1941, west of Gibraltar.