At the beginning of the Third Age the Dwarves were driven out of Moria, and some migrated to Erebor. As the Dwarves of Erebor would trade with the Men of the nearby towns of Dale and Lake-town, they needed a script to write in Westron (the lingua franca of Middle-earth, usually rendered in English by Tolkien in his works). The Angerthas Moria was adapted accordingly: some new cirth were added, while some were restored to their Elvish usage, thus creating the Angerthas Erebor.