All three ships were based at Massawa, Eritrea, during World War II and were sunk during the East African Campaign.

[1] The ships carried 393 long tons (399 t) of fuel oil[2] that gave them a range of 2,000 nautical miles (3,700 km; 2,300 mi) at a speed of 15 knots (28 km/h; 17 mph).

Leone and Pantera, along with Francesco Nullo and Nazario Sauro, shelled the convoy and its escort, inflicting some splinter damage to the leading transport ship, especially on one of her lifeboats, and launched at least two torpedoes aimed at HMAS Yarra, which dodged them.

Leone, Pantera and Sauro successfully disengaged but Nullo was chased by HMS Kimberley and forced to run aground on Harmil island, where she was later wrecked by RAF Blenheim bombers.

After being spotted and harassed by British aircraft, Pantera and Tigre reached the Arabian shores, where their crews scuttled them.