The Danes invaded Hertford several times, arriving by river from London. This was pretty easy as a ridiculous number of rivers flow through the town: notably the Beane, the Rib, the Lee (or Lea) and the Mimram. No-one knows where the Mimram got its name from. According to The English Place Name Society, it’s also been known over the years as the Memeram (925) Meran (1000) Maeran (1100) Maran (1577) and Mimeram (1728). And, as if that’s not complicated enough, a 1766 map calls it the Mimerum.