One of the Celtic dialects, is of the group known as the Goidelic, comprising Irish, Scottish Gaelic, and Manx. Scottish Gaelic and Manx developed through the migrations of Irish speakers in the late 4th cent. From the original settlement of Dalriada the Gaels spread northwards and eastwards through Scotland cutting through native Pictish resistance. Following the establishment of the Gaelic church on Iona by Columba in the 6th cent., the Gaels acquired the means of spreading both their authority and their language. In the 9th cent., Gaels and Picts were finally united under a Gaelic king, probably of mixed parentage. In the 11th cent., Malcolm Canmore, son of Duncan, came to the throne with the aid of English forces and began to introduce Anglo‐Norman customs and language. His descendants followed this policy and the Gaelic language was gradually replaced by English in state and church administration.
For 1755 it has been estimated that under a quarter of Scotland's population were Gaelic speakers—i.e. some 290,000. By 1971 Gaelic‐only speakers numbered no more than 477 out of 5,228,000. Support for the Gaelic language began in the 19th cent., and in 1882 it became possible to study Gaelic as part of a university degree course. Today children can be educated in Gaelic at the primary level and it can be studied at secondary level. Since these efforts to save the language have been in place, the number of speakers has increased.