This interesting surname is of early medieval English origin, and is an example of that sizeable group of early European surnames that were gradually created from the habitual use of nicknames. The nicknames were given in the first instance with reference to occupation, or to a variety of qualities, such as physical attributes or peculiarities, mental and moral characteristics, including supposed resemblance to an animal's or bird's appearance or disposition, or to habits of dress. In this instance the derivation is from the Middle English "titmose", titmouse, composed of the prefix "tit", of Old Norse origin, indicating small size, with the Olde English pre 7th Century "mase", the original name of the bird. The nickname was originally given to a small person. In the modern idiom the surname can be found as Titmus, Titmuss, Titmas and Tidmas. Recordings of the surname from London Church Registers include: the marriage of William Titmas and Timothea Moris on October 5th 1606, at St. Bride's, Fleet Street; the christening of John, son of William and Elizabeth Tidmas, on September 5th 1707, at St. Faith under St. Paul; and the christening of Elizabeth, daughter of Edward and Susanah Tidmas, on December 18th 1719, at St. Giles' Cripplegate. The first recorded spelling of the family name is shown to be that of Katheren Tetmos, which was dated September 10th 1564, marriage to Lambart Harmanes, at St. Giles' Cripplegate, London, during the reign of Queen Elizabeth 1, known as "Good Queen Bess", 1558 - 1603. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.