I have to deal with the question why in medieval French and Italian there was one name for draughts but in medieval Spanish two, marro and alquerque. To solve the problem we need information about Catalan and Castilian, two dialects (languages) of Spain.

 Catalan is the medium of communication in Catalonia, in the northeast of Spain. Catalonia was a county within the realm of Charlemagne, but in the 9th c. the national royal house gained independence. In the centuries that followed Catalonia expanded its power to the west (it conquered Aragón), to the northeast (it occupied parts of France), to the East (the Balearics) and to the south (Valencia). The position of Catalonia and the expansion to France carried weight with the Catalan culture and the Catalan language, which has more French influences than any other part of Spain.

 Together with Aragón and some other states, Castile was formed in the north of Spain as a christian reaction to the occupation of large parts of Spain by the Moors. The christian states rolled back the Moors to the south, systematically enlarging their territory. Castile gained the greatest success: in the 15th c. it had conquered almost every other Spanish state, so that we can speak of a unified Spain. And it stands to reason that Castilian had grown into the general Spanish language. In 1492 the last bulwark of the Moors fell: Granada.

 We have seen the following development. In the Middle Ages, both in Catalonia and in Castile draughts was played on a lined board. In France, the game was transferred to the chequered board; it received a new name: dames. This mode of playing and the name for the game were borrowed by the Catalans. The Castilians borrowed game and name from the Catalans. After a while the medieval form of draughts fell into disuse.

 In Catalan, French and Italian, continuations of Latin, draughts on the lined board was called marro, merelles, marella, appearing in several dialectical forms. The Castilian dialect is a continuation of Latin too. Therefore we may assume that also in medieval Castilian the word marro or a cognate form was used, but that this name was superseded by the name alquerque. Where did this word come from? Murray [1952:37-38] found that the word querque (al is a proclitic Arabic word) is not derivable from any Arabic root, and suggested the word may originally have meant 'lined board', referring to the word alquerque used in Castilian for a part of an oil mill. As a consequence, in her translation of the description of alquerque in the Alfonso manuscript Sonja Musser substituted the word alquerque for the word mill.

 The Italian linguist Alberto Zamboni [1973:45-46] made another etymological proposition for the Arabic word alquerque: the word derives from the Latin word calcul(us). I explain why this proposal is plausible.

 French merelles and Italian marella both meant 'draughts and morris', click here and here for evidence. The same goes for Catalan marro [Stoep 2005:128]. (These words had other senses too, for instance 'hopscotch'). They go back to Latin marrus = 'stone', 'gaming piece', dimunitive marrellus. This explains why board games as well as hopscotch received the same name: they are played with small stones (pieces). The clerk of Alfonso's court who was made responsible for the description of alquerque treated several board games which bore the name alquerque, successively alquerque de tres: 'three men's morris', alquerque de nuevo: 'nine men's morris' and alquerque de doze, a game played with (2x) twelve pieces. It is unlikely two different people independently would have thought up the same name for such different games. In other words, also the word querque must derive from a word meaning 'piece'. The Latin word calcul is appropriate, as a change [l] > [r] is far from unusual.