two u's written together, later fused into one letter.
W
the name says what it is: double u. Old English wrote this sound with a rune, wynn, and scribes on the continent wrote it uu; the ligatured form came into English with the Normans and took two centuries to push the rune out.
Andrews · Brewster · Brown · Crawford · Edwards · Fowler · Hawkins · Howard · Lawrence · Lawson · Lewis · Matthews · Owen · Powell
In the modern alphabet this letter is number 23 of 26. Before it comes V, after it X. The order itself is inherited: Latin took it from Greek, Greek from Phoenician, and the sequence has survived largely unchanged for about three thousand years. Every rearrangement since has been an insertion, not a reshuffle.
This is a consonant: it sets the hardness of a name and how it meets the next word. In a corpus of 315 surnames this letter opens 21 and closes 1. Among the 96 given names in the base it appears in 5. One occurrence per surname is the ceiling: no surname in the corpus repeats this letter.
William · Matthew · Andrew · Edward · Lawrence