Like her sister ships, Alessandro Poerio and Cesare Rossarol, she was named after a famous Neapolitan light cavalryman who helped defend Venice from attacks by the Imperial Austrian Army during the revolutions in 1848.

She had three Yarrow three-drum water-tube boilers with water pipes, two groups of Belluzzo steam turbines rated at 24,000 hp (17,897 kW), and two three-blade propellers.

On 30 December 1915 she became part of the 2nd Scouting Group of the 4th Naval Division along with her sister ships Alessandro Poerio and Cesare Rossarol, based at Venice.

[9] Escorted as far as the Austro-Hungarian defensive barrage by Guglielmo Pepe and Cesare Rossarol and supported by the destroyers Alpino and Fuciliere and the coastal torpedo boats 40 PN and 46 OS, the destroyer Zeffiro, under the command of Capitano di fregata (Frigate captain) Costanzo Ciano and with Lieutenant Nazario Sauro, an Italian irredentist, aboard as pilot, entered the port of Poreč on the western side of Istria, a peninsula on Austria-Hungary's coast, at dawn on 12 June 1916.

[14] On 1–2 November 1916, Guglielmo Pepe, Alessandro Poerio, Francesco Nullo, and Giuseppe Missori made ready to provide possible support to an incursion by MAS motor torpedo boats into the Fasana Channel on the southwest coast of Istria.

[11] An Austro-Hungarian Navy force consisting of the scout cruiser Helgoland and the destroyers Balaton, Csepel, Lika, Orjen, Tatra, and Triglav left Cattaro on 18 October 1917 to attack Italian convoys.

At 06:30 on 19 October 1917, Guglielmo Pepe, with Contrammiraglio (Counter admiral) Biscaretti embarked, got underway from Brindisi with Alessandro Poerio and the destroyers Pilade Bronzetti, Insidioso and Simone Schiaffino to pursue the Austro-Hungarians.

The destroyers Ippolito Nievo and Rosolino Pilo and the British light cruiser HMS Weymouth diverted from a voyage from Vlorë (known to the Italians as Valona), Albania, to Brindisi to join the pursuit.

[11] On 2 October 1918 Gulglielmo Pepe, Alessandro Poerio, Cesare Rossarol, Ippolito Nievo, and Simone Schiaffino were at sea with the battleship Dante Alighieri and the scout cruiser Carlo Alberto Racchia to provide distant cover for a British and Italian naval bombardment of Durrës.

In 1922, the city of La Spezia awarded battle ensigns to Guglielmo Pepe, the scout cruiser Falco, the destroyer Angelo Bassini, and the torpedo boat Premuda.

[17] The Nationalists viewed the Italian price as excessive given the age of the destroyers, which were reaching the end of their useful service lives,[17] and Italian Prime Minister Benito Mussolini demanded payment in cash in foreign currency,[18] but after lengthy and difficult negotiations, the Nationalists agreed to buy Alessandro Peorio and Guglielmo Pepe for just over 5 million pesetas each.

[17] Old ships by 1937, Guglielmo Pepe and Alessandro Poerio had worn-out propulsion machinery and, in the view of the Spanish Nationalists, inadequate armament.

[17] The flotilla was assigned to convoy escort duties, support to ground operations, the interdiction of merchant ships of the Spanish Republican faction, and antisubmarine patrols.

Capitán de fragata (Frigate Captain) Francisco Regalado Rodríguez, a future admiral and Minister of the Navy, took command of the flotilla on 5 December 1937.

[17] On the afternoon of 22 February 1938 she joined Melilla and Velasco in escorting the merchant ship Pasajes, which was making a voyage in the Balearic Islands from Formentera to Mallorca.

[17] The destroyers and gunboats thus missed the Battle of Cape Palos, in which a Spanish Republican Navy force sank Baleares on the night of 5–6 March.

On 3 November 1938 she gotunderway as part of a Nationalist squadron heading for the Strait of Gibraltar, but a major mechanical breakdown forced her to proceed instead to Ceuta on the coast of North Africa, escorted by the light cruiser Navarra.

Among Teruel′s most important achievements during the war were the capture of the Soviet steamer Zyrianin and of the American tanker Nantucket Chief, which the Nationalists later handed over to international authorities at Gibraltar.

[17] On the morning of 22 October 1940 Teruel, Huesca, and the destroyer Churruca arrived in Barcelona carrying 100 students from the Naval School in San Fernando on a training voyage that visited several ports.

[17] On 30 June 1941, Teruel left Cadiz with the Spanish High Commissioner in Morocco and his family aboard bound for Ceuta and Tetouan on the coast of North Africa.