It was with the encouragement of William Camden that Speed began his "Historie of Great Britaine", which was published in 1611. Although he probably had access to historical sources that are now lost to us (he certainly used the work of Saxton and Norden), his work as a historian is now considered secondary in importance to his map-making, of which his most important contribution is probably his town plans, many of which provide the first visual record of the British towns they depict. In the years leading up to this point, while his atlas was being compiled, he sent letters to Robert Cotton, part of the British government to ask for assistance in gathering necessary materials.