 Also authorised was the North British Railway (to build from Edinburgh to Berwick, and the Scottish Central Railway, to build from the Edinburgh and Glasgow line near Castlecary to Perth, and the Caledonian Railway, to build from Glasgow and Edinburgh to Carlisle.The fragmented nature of these authorisations resulted in an immediate search for alliances, and even before much construction had taken place, some companies' boards thought it essential to seek to control as much territory as possible, by friendly alliance or by takeover.Many of these alliances were quickly agreed, and in many cases without much strategic thought.