During the high and late middle ages, Genoa was a dominant force in Mediterranean commerce. This study examines the relationship between Genoa and the southern French town of Montpellier in three historical eras: the twelfth century to about 1180; from the 1180s to about 1270; and from 1270 through the mid-fourteenth century. In the first era Genoa, along with Pisa, exercised economic hegemony over the coast of southern France. In the second period, Montpellier gradually emancipated itself from Genoese commercial control. In the third era interaction between Montpellier and Genoa became increasingly complex because of the growth of French influence in Languedoc. The French monarchy sought to control southern French commerce with a requirement in 1278 that Italian merchants reside in Nimes and trade through Aigues-Mortes, and later in the 1330s with the offer of a transport monopoly over goods from southern France to Genoese admirals Doria and Grimaldi. Montpellier resisted these French efforts, invoking its commercial independence and political allegiance to the Majorcan king. By the mid-fourteenth century Genoese pretensions to commercial dominance over Montpellier were hollow reminders of the past, but the Genoese legacy of business technology remained strong.