Rara & singularis commixtio lucis, & tenebrarum! At the beginning of the studies on Arab-Byzantine coinage

During the pioneering studies on Islamic coins, one of the most controversial and difficult to understand themes was to explain the simultaneous presence of Christian symbols alongside Islamic ones, such as the name of the prophet or the shahada (one of the Five Pillars of Islam). Over the centuries some issues were correctly attributed to the Urtukids, others remained unexplained, such as those now attributed to the Arab-Byzantine series. The orientalists of the late eighteenth century, including Simone Assemani, remained elaborated only erudite and uncertain explanations, far from a correct reading of what was legible on the coins. Gaetano Cattaneo, the curator of the numismatic collections in Milan, was the first who identified the exact classification of these coins, thanks to a follis/fals of the Tiberias mint, coming from a Venetian collection dispersed in the trade market in Milan.