Historically the spellings of non-English names accord with the way in which these names have normally been pronounced in English. Thus Roma has become Rome, Lisboa has become Lisbon and Bruxelles has become Brussels. This convention has remained largely unchanged over the years.
However, in those parts of the world with entirely different systems of writing and spelling there have been some problems. Very often the form of name used in English has borne little relationship to the actual name and the way it may be written. Thus the names of such Chinese capital cities historically known as Peking, Nanking and Chungking do not correspond with the Chinese pronunciation and the way in which they are written in the Chinese script. In the late twentieth century the adoption of a new transliteration by the Chinese has come to be accepted as being the standard form. As a result the names of these three Chinese capitals are now transliterated as Beijing, Nanjing and Chongqing using the spellings specified by the Chinese themselves. Sometimes this can cause confusion as the new spelling may not correspond at all with the usual western pronunciation. Many new and unfamiliar spellings, such as Qin for Chin and Qing for Ching, have had to be accepted but they can cause confusion among those who find the new transliteration difficult to cope with.
In the case of India, many of the place names, such as Bombay and Calcutta, were originally given by European colonialists and these spellings were in use until quite recently. Major changes did not come about until the early twenty-first century and these have not always come to be widely used. While Bombay is now generally written as Mumbai, names such as Chenai (Madras) and Bharuch (Baroda) have proved less easy for Europeans to accept.
In the case of the spelling of Mongolian names, the fashion for Chinese transliteration has spread to what was for many centuries a Chinese province but which has since the Second World War been an independent country. However, the Chinese transliteration has not been followed here because the older spelling has continued to be widely used both in Mongolia and elsewhere. Thus the spelling Karakorum has been used in preference to Qaraqorum. However, the Mongolians themselves have transliterated names such as Ulan Bator as Ulaan Baatar and this has been followed here.
Some names have a historical use which may have literary and other associations. After the play by Christopher Marlowe the name of the fourteenth-century central Asian conqueror came to be known as Tamburlaine. This was an Elizabethan Anglicization of Timur or Temur Lenk, meaning Timur the Lame. Today the most usual English spelling is Tamerlane, although other transliterations may still be found.
In a similar manner the thirteenth-century Mongol khan and emperor became known as Kubla Khan after the poem by Coleridge. Qubilai Khan, the Chinese transliteration of his name, is accepted here since, although a Mongolian, he was the founder of the Chinese Yuan dynasty.
Overall, the author has aimed to use what is judged to be the most generally accepted and acceptable spellings. In the case of European spellings using the Latin script, the usual English conventions have been followed. Elsewhere while note has been taken of new spellings, and in many cases these have been adopted, in other cases those judged to be most easily understood and accepted by an English-speaking reader have continued to be used.