Phonological history of Spanish coronal fricatives

In Spanish dialectology, the realization of coronal fricatives is one of the most prominent features distinguishing various dialect regions. The main three realizations are the phonemic distinction between /θ/ and /s/ (distinción), the presence of only alveolar s (seseo), or, less commonly, the presence of only a denti-alveolar s̟ that is similar to /θ/ (ceceo). While an urban legend attributes the presence of the dental fricative to a Spanish king with a lisp, the various realizations of these coronal fricatives are actually a result of historical processes that date to the 15th century. A persistent urban legend claims that the prevalence of the sound /θ/ in Spanish can be traced to a Spanish king who spoke with a lisp, and whose pronunciation spread by prestige borrowing to the rest of the population. This myth has been discredited by scholars. traces the origins of the legend to a chronicle of Pero López de Ayala which says that Peter of Castile "lisped a little" ("ceceaba un poco"). However, Peter reigned in the 14th century and the sound /θ/ began to develop in the 16th century (see below). Moreover, a true lisp would not give rise to the systematic distinction between /s/ and /θ/ that characterizes Standard Peninsular pronunciation. For example, a lisp would lead one to pronounce siento ('I feel') and ciento ('hundred') the same (as [ˈθjento]) whereas in standard peninsular Spanish they are pronounced [ˈsjento] and [ˈθjento]. For native speakers of seseo varieties, in which /θ/ is absent, the presence of this phoneme in speakers of European Spanish does not appear strange. However, learners of Spanish in North America, where people are more familiar with seseo pronunciation, may misinterpret it as lisping. The misnomer "Castilian lisp" is used occasionally to refer to this aspect of Peninsular pronunciation (in both distinción and ceceo varieties). In the 15th century, Spanish had developed a large number of sibilant phonemes: seven by some accounts, eight by others (depending on whether /d͡ʒ/ and /ʒ/ are considered contrasting), more than any current dialect.