Commercial exchanges occurred between the Carolingian and Abassid realms, and Arabic coins are known to have spread in Carolingian Europe in that period.[5] Arab gold is reported to have circulated in Europe during the 9th century, apparently in payment of the export of slaves, timber, iron and weapons from Europe to Eastern lands.[6] As a famous example, the 8th century English king Offa of Mercia is known to have minted copies of Abbasid dinars struck in 774 by Caliph Al-Mansur with "Offa Rex" centered on the reverse amid inscriptions in Pseudo-Kufic script.[7][8]