This is a famous Scottish surname, whose blood it is claimed, "runs in every noble Scottish family", may be of German origin. According to ancient mythology, in the11th century a party of Germans (Anglo-Saxons?) landed on the east coast of Scotland, and assisted the native population in defeating the Danes. The Germans were apparently known as the "Catti tribe", and they were lead by one Robert. As a result of their success they were granted lands in East Lothian, where for many centuries they were prominent land holders. There seems no reason why this should not be true, although whether the Catti were granted lands freely, or simply took them by the power of the sword, is a mute point. What is beyond argument is that the Keith's have never had the prefix "Mac", and this is often used as an argument that the name is not of Scottish or Gaelic origins. However neither have the Clan Douglas, and you canot get much more Scottish than them. Early examples of the surname recording include Bernard de Keth, who witnessed a charter in Kelso in the year 1201, and Sir George Keith, described as being (quote) "the Great Marischal of Scotland in 1315, and leader of the Scots's cavalry at Bannockburn". He was killed at the battle of Durham in 1346. Andrew Keth, the 4th Earl Marischal, was a hostage for the release by the English of King James 1st in 1425, whilst George Keith (1693 - 1778) was the 10th Earl Marischal, but was exiled from Scotland for being a Jacobite.