This interesting surname, of Irish origin with variant spellings Dreinan, Drinan, Drinnan, and Drynan, is an Anglicized form of the Gaelic "O'Draighneain" meaning "descendant of Draighnean", a byname from a diminutive of "draighean" meaning "blackthorn". The sept originated in Connacht where it has been frequently changed to Thornton by semi-translation. The surname dates back to the mid 12th Century (see below), and other early recordings include, John, son of James and Margaret Drennan, who was christened on June 20th 1611, at St. Martin in the Fields, Westminster, London. The United Irishman, Dr. William Drennan (1754 - 1820), was the poet who first called Ireland "the Emerald Isle". His two sons, John and William, were also poets. One Margaret Drennan, aged 57 yrs., together with her, daughter Biddy, aged 25 yrs., were famine emigrants who sailed from Belfast aboard the "Monterey", bound for New York in April 1847. The first recorded spelling of the family name is shown to be that of Gillachiarain O'Draighnen of Fore, which was dated 1163, in the "Four Masters of County Westmeath", Ireland, during the reign of King Henry 11, known as "The Builder of Churches", 1154 - 1189. 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.