This is a famous Irish clan surname. It derives from the pre 10th century Gaelic O'Madain, which translatea as 'The descendant of the son of the hound'. Most Irish surnames suggest an element of what must have been a desciptive nickname, O'Kennedy, as an example describes 'The descendant of the ugly headed one!' In this case the name has been anglicized as Madden, a surname also found in England, Madigan and MacAvaddy. The sept originated from lands on the River Shannon in Co.Galway in the West of Ireland and extended to Co.Offaly, in total over 25,000 acres. Even today Madden nameholders are still numerous in that part of the country. The Madigans are regarded almost exclusively as a Clare-Limerick family, although a branch of the Co. Galway Maddens, as are the Madigans of Counties Antrim and Derry in Ulster. Early surname holders have included the Rev. Samuel Madden (1680 - 1760) and a famed philanthropist, whilst Richard Madden, (1798 - 1886) was the author of 'The United Irishman'. During the infamous 'Potato Famine' of 1846, many name holders emigrated to both England and America. Amongst these were Walter Madden and his wife Mary, and their children Richard aged five and Alice, a baby, who sailed, probably from Galway, bound for New York on the ship 'Junius ' on May 1st 1846. Another recording is that of Hannah Madigan aged twenty two, who left Belfast on the ship 'Howard' for New York, on July 23rd 1846. The coat of arms is the distinctive white eagle on a black field, attacking a gull. The first recorded spelling of the family name is shown to be that of Dermot O'Madadhain, which was dated circa 1100, chief of the Ui Maine, Connacht, during the reign of King Henry Ist of England, known as 'The Administrator', 1100 - 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.1135.