An irregular marriage could result from mutual agreement, by a public promise followed by consummation, or by cohabitation and repute.All but the last of these were abolished by the Marriage (Scotland) Act 1939, from 1 July 1940.There is a distinction between so called religious marriages, conducted by an authorised celebrant, and civil marriages, conducted by a state registrar, but anyone over the age of 21 can apply to the Registrar General for authorisation to conduct a marriage under s12 of the Marriage (Scotland) Act 1977, and no form of religious ceremony is necessary.
Gretna's famous runaway marriages began in 1753 with the passing of Lord Hardwicke's Marriage Act in England.
The Act required consent to the marriage from the parents if a party to a marriage was not at least 21 years old.
Other motives for Gretna marriages were to avoid publicity or to marry immediately.
In 1856, Scottish law was changed to require 21 days' residence for marriage, and since 1929 both parties have had to be at least 16 years old (though there is still no parental consent needed).
In the eighteenth and nineteenth centuries, marriage laws in Scotland encouraged the practice of couples wishing to marry eloping from England to Scotland.
With transport less developed, many of these marriages were at Gretna Green, the first Scottish settlement on the main West Coast route from England; hence the term Gretna Green marriage for marriages transacted in a jurisdiction that was not the residence of the parties being married, to avoid restrictions or procedures imposed by the parties' home jurisdictions. Portpatrick in Wigtownshire was used by couples from Ireland, because of the daily packet boat service to Donaghadee.Marriage in Scotland is recognised in the form of both civil and religious unions between individuals.Historically, the law of marriage has developed differently in Scotland to other jurisdictions in the United Kingdom as a consequence of the differences in Scots law and role of the separate established Church of Scotland.A marriage by "cohabitation with repute" as it was known in Scots Law could still be formed; popularly described as "by habit and repute", with repute being the crucial element to be proved.In 2006, Scotland was the last European jurisdiction to abolish this old style common-law marriage or "marriage by cohabitation with repute", by the passing of the Family Law (Scotland) Act 2006.A further law change was made in 1940 to abolish these irregular marriages by declaration. Gretna Green remains a favoured location for marriage because of its romantic associations, with Dumfries and Galloway (the council area containing Gretna Green) the most popular area to get married in Scotland in 2015 (4,395 marriages in Dumfries and Galloway, out of a total of 29,691 marriages throughout Scotland). Marriage must be between two otherwise unmarried people.