I have Millers in my family tree, beginning with William Miller/Millar b 1799 in Cockermouth. His children included Isaac Miller b1822 in Richmond, Yorks. This started a whole string of Isaac Millers through subsequent generations, and also Phillis or Phyllis as a common name. Most of them were Hawkers, of china, tin goods and later fish. Although they certainly travelled, I don't think that they were Travellers, if you see what I mean. They always appear in censuses either with family in houses or staying as lodgers