This unusual and interesting surname is of Scottish origin, and is an Anglicized form of the Gaelic "Mac Fhilib", a patronymic from a Gaelic form of the given name "Philip". Philip is derived from the Greek personal name "Philippos", meaning horse-lover. Some of the namebearers are said to have been standard-bearers to the Campbells of Dunstaffnage, others are included as septs of MacDonald of Glencoe and of MacDonnell's of Keppoch; MacKillop also occurs as a surname in Arran. The surname development since 1433 (see below) includes the following: William MaKillop (1526); Donald M'Gillip (1532); Malcum M'Killib (1547); and Tharlocht M'Killib (1649, Lochtay). The modern surname can be found recorded as McKillop, McGilp, Killip and Keillips. One Robert Makillip was a witness in the Register of the great Seal of Scotland in 1545. Among the recordings in Scotland is the christening of Thomas, son of James McKillop and Margaret Hay, on July 9th 1745 at Edinburgh, Midlothian. The first recorded spelling of the family name is shown to be that of Finlaius Macpilibh (priest), which was dated 1433, recorded at Argyll, Strathclyde, Scotland, during the reign of King James 1 of Scotland, 1406 - 1437. 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.