This interesting name is of Medieval Irish-Norman origin, although it is also widespread in England, and is the patronymic form (Fitz denoting 'son of') of the Old Norse personal name 'Sigmundr', a name meaning victory. The first records of this name in Ireland are of a period after the Anglo-Norman Invasion of 1170, and among the Norman families brought to County Down by John de Courcy in 1177 were some called Fitzsimon, while others followed the Prendergasts to Mayo early in the next century. The most important line of this family came to Ireland from Simonshide in Hertfordshire and settled in The Pale (an area in Dublin) in 1323, since then they have been leading gentry in Counties Dublin and Westmeath. Although the majority of records show this name as FitzSimon; FitzSymon(s), FitzSymonds and FitzSimmons are forms also in use. In America, Irish born Thomas FitzSimmons (1741-1811) was one of the leading men in the War of Independence. The first recorded spelling of the family name is shown to be that of Hugo Le FizSimond, which was dated 1325, in the Parliament Writs, London, during the reign of King Edward 11, known as 'Edward of Caernafon', 1307-1327. 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.