Recorded in several spelling forms including McMurdo, McMurdoe, McMurdy, Murdo, Murdie and Murdy, this is a Scottish surname. It derives from the popular surname McMurdoch, itself derived from the Gaelic pre 10th century Mac Mhurchaidh, meaning, 'the son of the sea warrior'. This is from the elements Mac, meaning 'son of', with mur meaning 'sea', and cath, 'a warrior'. The surname as McMurdo was originally recorded in the Mull of Kintyre and the Isle of Arran, and later in the 16th Century in Dumfriesshire, where the first spelling was as M'Murday. Evarus Makmurdie was recorded as being heir to his father John Makmurdie in 1602, whilst Angus M'Murdie of Killilego is on record in the parish of Dunskoir in the year 1675. A later recording is that of William Murdie of Stronchurbie, Assynt, who died in 1941. The McMurdo family is connected with the parish of Dunscore and gave its name to the property of M'Murdiston. The name is also spelt Murdochson and Murdoson in its anglicized forms, and is occasionally used as a synonym of Murtagh. Surnames became necessary when governments introduced personal taxation. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.