•In the year 1595 John was born, Henry IV of England declared war on Spain, the Dutch begin to colonize East Indies, Sir Francis Drake and Sir John Hawkins leave Plymouth on the last voyage to Spanish mainland, and the English army finally abandons the bow and arrow as a weapon of war.
The Norsemen settled in eastern England, the area known as the Danelaw, and carried this name with them. There, it developed into the names Thurstan, Thurston, and Thurstin. However, they also settled in Normandy, in Northern France. Here, the Norsemen quickly adopted French. French, however, lacks the interdental fricative "th" found at the beginning of Thorsteinn, so the French-speaking descendants of the first Norse settlers began to substitute a simple stop "t" for "th" (as the French still often do). As a result, the pronunciation of the original Norse THORSTEINN was transformed first into Turstan, Tourstan, Tourstain, and, with the gradual loss of the weakly pronounced word-internal consonants? r and -s, the pronunciations Toustain and Toutain appeared (the spellings I give here are those of Old French). Toutain is the form that seems to be the precursor of modern Tuten (Tutin, etc.).
In 1066, William the Conqueror and the other Norman French invaded England, and, logically, their surnames went with them. Toutain became Tutin, and has survived today as such in England (e.g., the London stage actress Dorothy Tutin). Of course, until standardization of spelling began in the 1700s, people spelt their names as best they could, in line with local pronunciation, but with no fixed rules. This probably accounts for the wide variation in spelling and pronunciation today: Tutin, Tuten, Tutan, Totten, Tootin, etc. (the unstressed vowel i? is often pronounced as a schwa, as in "but", so this second vowel in the name is particularly susceptible to spelling variation).
Of course, these days we hardly even pronounce a schwa, just a "toot" and "n"!