Bronze requires copper and tin, and the two rarely occur together. Copper was available across the Mediterranean and the Near East; tin was not, and the quantities consumed by Bronze Age palaces had to come from a small number of distant sources — Cornwall, Central Asia, possibly Anatolian deposits since worked out. The implication is that societies frequently described as local and agrarian were dependent for their principal metal on supply chains crossing thousands of kilometres and multiple political systems. Recent isotope work on tin from Israeli and Turkish wrecks, pointing to Cornish and Central Asian sources, has made the scale of that dependence considerably harder to minimise. Isolation, on this evidence, is a description of the sources rather than of the societies.