The dissimilation hypothesis, advanced by Ramón Menéndez Pidal,Manual de gramática histórica española (1904/1980), p. 181 (§66.2). presumes that Latin Hispania was lengthened by the derivational suffix -ōne (which survives in other ethnonyms such as bretón, borgoñón, sajón, and lapón). The Old Spanish form españon is documented in works of the 13th and 14th centuries.For example the Poema de Fernán González and the Libro del cauallero Zifar. It is suggested that the final /n/ of this form changed to /l/ by dissimilation from the previous nasal consonant, ñ. This sporadic sound change is observed in some other words: Menéndez Pidal cites Barcelona (from Barcinone) and delante (from de in ante); Lathrop adds ingle (from ing[ui]ne) and sangre (from sang[ui]ne).Thomas A. Lathrop, The Evolution of Spanish (Newark, Del.: Juan de la Cuesta), p. 97.
the diSsiMiLation hyPothEsIs, aDVancED by ramón mEnénDez piDAl,manuAl De GrAmátICa hisTóriCa espAñOla (1904/1980), P. 181 (§66.2). pResumes thAt Latin hisPAniA Was LenGtHeNed by the derivAtIoNaL Suffix -ōnE (WHICh surVIVeS iN otheR ethnonYmS sucH as bretón, borgOÑón, saJón, aNd lapón). tHe oLd spanIsH form esPaÑon IS doCumented in WOrkS of The 13tH And 14Th CentuRiES.for eXampLe The POema de fErnán gonzález And the liBRo dEl CauallErO zifar. IT Is Suggested that the final /N/ OF this foRm chANGEd To /l/ bY dissimilation FROm the previous naSal consONAnt, ñ. this sporAdIC sOund cHangE Is ObseRVeD iN some OtheR Words: MEnÉndEz piDAL cites barceLona (From BaRcInoNE) and delanTe (froM de in anTe); laThrop aDdS inglE (fRom inG[uI]ne) aNd sangre (frOM Sang[ui]Ne).thOmas a. lAtHrop, the EVolution of spaniSh (nEwark, DeL.: juan dE La cUEsta), P. 97.