Wikipedia
The Lothians was one of the eight electoral regions of the Scottish Parliament ( Holyrood) from 1999 to 2011. Nine of the parliament's 73 first past the post constituencies are sub-divisions of the region and it elects seven of the 56 additional-member Members of the Scottish Parliament (MSPs). Thus it elects a total of 16 MSPs.
The Lothians region shares boundaries with the South of Scotland and Central Scotland regions, and is connected with the Mid Scotland and Fife region by bridges over the Firth of Forth.
As a result of the First Periodic Review of Scottish Parliament Boundaries it is largely replaced by the Lothian region.
Prior to its uniform adoption of proportional representation in 1999, the United Kingdom used first-past-the-post for the European elections in England, Scotland and Wales. The European Parliament constituencies used under that system were smaller than the later regional constituencies and only had one Member of the European Parliament each.
The constituency of Lothians was one of them.
When it was created in Scotland in 1979, it consisted of the Westminster Parliament constituencies of Edinburgh Central, Edinburgh East, Edinburgh Leith, Edinburgh North, Edinburgh Pentlands, Edinburgh South, Edinburgh West, Midlothian, West Lothian, although this may not have been true for the whole of its existence.