of columns. While some smaller columns move quickly from the animals to the plain shaft below, the largest and grandest examples have a long intervening section with double volutes at the top and, inverted, at the bottom of a long fluted square zone, although the shaft of the column is round. At the top of the round fluted shaft are two sections with a loosely plant-based design, the upper a form of "palm capital", spreading as it rises, and the lower suggesting leaves drooping downwards. Other capitals have the animals and the two lower plant-based elements, but not the section in between with the volutes; the example in Chicago is of this type. There are various small mouldings between the various elements, reflecting a Greek style. The horns and ears of the animals are often separate pieces, fitting into the head by square plugs. The columns were polished and at least the capitals were painted, in the case of wooden ones on a plaster coating. The style reflects influences from the many cultures that the Persian Empire conquered including Egypt, Babylon, and Lydia, as well as Greece, where the Persians had only temporary success; the final result is distinctively Persian. It is thought the stone columns that survive were preceded by wooden versions, and these continued to be used. The move to stone may have come when sufficiently large trees for the biggest buildings became difficult or impossible to source. The column shafts can be as tall as 20 metres. The base is in stone even for wooden columns, and sometimes carries an inscription saying which king erected the building. Most are round, but an early square type has two steps. Use and influence The full form of Persian column seems only to have been used at a few sites outside Persia around the empire in the Achaemenid period, in Armenia and even Levantine colonies in Iberia. The columns influenced the Pillars of Ashoka erected in India some 80 years after Alexander the Great destroyed the Persian Empire, and other imperial buildings in the architecture of the Maurya Empire. The much smaller Mathura lion capital of the 1st century CE shows clear influence. They can be seen in relief decoration around Buddhist stupas in Gandhara in the 2nd or 3rd century CE, and Persian columns decorate the Karla Caves and Nasik Caves. The style did not develop in Persia itself,