The con­flict that ra­va­ged Spain bet­ween 1936 and 1939, dub­bed by some historians“War of the Thou­sand Days” was in Asturias, in mi­li­tary terms, a shor­ter du­ra­tion: 15 months, bet­ween July 1936 and Oc­to­ber 1937 where vir­tua­lly no cu­rrent day withoutcombat. Control of Oviedo (As­tu­rias ca­pi­tal) by the re­bels du­ring the pe­riod of hos­ti­li­ties­found the mi­li­tary ac­tions un­der­ta­ken in Asturias: the city was en­cir­cled for 3 months and then sent to Ga­li­cia pre­ca­riously th­rough a na­rrow “co­rri­dor “un­til Franco’s vic­tor­yoc­cu­rred in the North.

That ha­ll­way or co­rri­dor, star­ted from Oviedo in the west to the vi­llage of San Clau­dio and con­ti­nued in the di­rec­tion of El Es­cam­plero across the Las Re­gue­ras county be­fore cros­sing the Na­lón ri­ver th­rough the Pe­ña­flor Bridge and end in Grado. Twenty ki­lo­me­ters de­fen­ded for these po­si­tions: Hill of Pando, Sie­rra del Na­ranco and Villaverde, the moun­tains of La Trecha, Otero, Guilero, Ania, La Pa­rra, Mount Los Pi­nos and this saw the Pico del Arca, and the crest of Co­ta­nie­llo and Manga (also in this range ha­ras­sed by the Re­pu­bli­can po­si­tions of Pedroso, Carballinos and La Escrita).

The ri­ver be­came, in its lo­wer reaches, from Pe­ña­flor to its mouth at the es­tuary of San Esteban, in front of the front and south of the in­ter­sec­tion of the saw on two fronts, Nalon, with each con­ten­der side of the ri­ver and the front hall, which cros­sed the ri­ver Peñaflor,thereby be­co­ming the saw en­clave of great im­por­tance, since its do­mi­nance meant to­main­tain the co­rri­dor around Oviedo-Grado and others, the op­por­tu­nity to cut and iso­late Oviedo.

Af­ter the fai­led Re­pu­bli­can at­tack oc­cu­rred in Oc­to­ber 36 and led to the es­ta­blish­ment of these two fronts, the mi­li­tary com­mand go­vern­ment pre­pa­red a new ope­ra­tion that be­gan on No­vem­ber 27. In the highlands, making Ci­mero peak was an ep­he­me­ral­suc­cess, since the po­si­tion was re­ta­ken by the rebels. The Battle of Mount Los Pi­nos (near Grado), across the river, where se­ve­ral bat­ta­lions with the sup­port of new Rus­sian tanks mo­ved reaching the cen­ter of the town of Grado, made​clear the vul­ne­ra­bi­lity of the ha­ll­but fai­led to stran­gle him.

On Fe­bruary 37 the re­pu­bli­can army laun­ched its fi­nal at­tack on Oviedo. Fifteenbrigades with the sup­port of al­most one hun­dred pie­ces of ar­ti­llery, do­zens of ar­mo­red vehi­cles, air sup­port and two ar­mo­red trains, attacked the ca­pi­tal of As­tu­rias and gra­dethe co­rri­dor of Oviedo-Grado. But the only suc­cess for the at­ta­ckers was to take the Loma del Pando, fai­ling again at­tempt to cut com­mu­ni­ca­tions in the vi­ci­nity of Peñaflor. The Nort­hern Re­pu­bli­can Army would ma­te­ria­lly and mo­ra­lly wea­ke­ned since then. The Re­pu­bli­can As­tu­rias then went to the de­fense un­der the motto “Fortify is overcome.”

Even try to take the aisle in Au­gust, star­ting from the po­si­tion of the saw. It was the last Re­pu­bli­can of­fen­sive on the nort­hern front. It took place on Au­gust 1, 37 with the aim of ta­king po­si­tions Ci­mero, La Manga, Cotaniello and Arca, defended by the 3rd Bat­ta­lio­nof the re­gi­ment Me­rida 35 and an amal­gam of com­pa­nies from dif­fe­rent sour­ces (Ma­rine Corps, the Third of Re­quete Gallego, members of the In­fan­try Re­gi­ment Za­ra­goza , I.R. Zamora, and one sect. of the 10th Company Sappers).

Two di­vi­sions of in­fan­try bore the brunt of the ope­ra­tion, the “Di­vi­sion de Cho­que As­tu­riana” and Re­serve Div III Corps of As­tu­rias, and the Mon­ta­ñesa Di­vi­sion in re­serve, ar­ti­llery sup­port, air­craft and ar­mo­red vehicles.

The vic­tory see­med se­cure the ma­ni­fest su­perio­rity of men and wea­pons, but the ope­ra­tion failed. The ar­ti­llery re­pu­bli­ca­na­que should pu­nish the enemy po­si­tions be­fore dawn to fa­ci­li­tate in­fan­try as­sault, but it de­la­yed its ac­tion, and could not take ad­van­tage of the dark­ness to ap­proach unseen. In ad­di­tion, cal­cu­la­tion errors led to the fire of the bat­te­ries do white Re­pu­bli­cans in his own strength. Government air­craft also suf­fe­red se­ve­ral mis­haps suf­fe­red: two air­craft co­lli­ded in Gi­jón when pla­ced in trai­ning and anot­her four were hit by enemy air­craft, two of them shot down in the field. It fa­red bet­ter ar­mor, Leat­her re­cei­ved with an­ti­tank gun fire. The at­tack left him in a fight one day more than 600 dead on the field de­ba­ta­lla and a huge num­ber of wounded

Af­ter this fai­lure, the Nort­hern Army for­ces un­der­took no more of­fen­sive actions. Franco or­de­red the cam­paign on the Can­ta­brian coast were for­ced to stay in cons­tant de­fen­sive un­til the fall of the nort­hern front in Oc­to­ber 1937.