The Portuguese Navy had struggled to secure funding for new ships after the 1890s, when a number of protected cruisers and smaller craft had been built.

After the toppling of the Portuguese monarchy in 1910, the navy submitted another large construction plan in 1912, which the new republican government passed (and then reduced in scope in 1913).

The ships had straight stem and a short forecastle deck that terminated forward of the conning tower.

The engines were rated to produce 11,000 shaft horsepower (8,200 kW) for a top speed of 27 knots (50 km/h; 31 mph).

At a more economical speed of 15 knots (28 km/h; 17 mph), the ships could cruise for 1,600 nautical miles (3,000 km; 1,800 mi).