<p>During its most prosperous period, from about 1345 to near the end of the 15th century, Coventry is said to have been the fourth largest city in England, and in 1523-7 its subsidy assessment was still higher than any save those of London, Norwich, Bristol and Newcastle-upon-Tyne. But the cloth trade was declining and the art of making blue thread, flourishing in the period and giving rise to the expression ‘true as Coventry blue’, seems to have been lost by the middle of Elizabeth’s reign.