Christopher = Christ carrier. Biblical, after a ford-porter who carried Jesus.
Marden. = Corruption of Maderer, a gatherer of plants for the dyeing industry.
Most English peasants never had surnames until it became difficult to differentiate between the locals with the same first names. The, "James-on-the-Hill" became James Hill. William-of-the-sheepfell-bottom became Bill Shufflebottom. Thomas-the-carpenter is an example of a trade related name, Crookshank and Armstrong of physical characteristics.
It used to be possible to get large books which listed the majority of English surnames. It was also easy to bore your pals by telling them what their ancestors did or where they lived....