John Gallagher:

States struggled to work out their role in these rapidly changing systems. Private mail presented different problems: should couriers working for state-funded postal services be allowed to carry post on behalf of paying customers? For the states that underwrote postal systems, this was risky – it increased the risk of robbery since private mail often included money and valuables – yet attractive: an efficient postal service subsidised by private clients would be less of a drain on state resources. Controlling the carriers of private mail also made surveillance simpler. As time went on, the price of sending a private letter fell, so that more ordinary people were involved in the flow of mail and news: ‘What had started as a state privilege had become a preferred public service.’ Crucially, by the second half of the 17th century, the postal stagecoach had become the essential vehicle of European travel, carrying passengers at the same speed as it delivered the mail. The machinery of the post – its itineraries and printed guides, inns as relay stations, couriers with local knowledge – adapted seamlessly to facilitate a new era of tourism and would form the backbone of the Grand Tour. The infrastructure of posts and couriers that served states and merchants laid the foundations for a revolution in communications.