Originally built by the Dunedain Anarion in the late Second Age, it was one of the three great cities of Gondor, along with Minas Ithil and Osgiliath, and was called Minas Anor. When Minas Ithil fell, it was renamed to Minas Tirith( the Tower of Guard). Also, it became the capital of gondor after the plague in Osgiliath. Fun fact: Another Minas Tirith was built in the First Age by elves.
Only Osgiliath herself was able to restrain the grief-stricken city from rushing headlong into battle, despite being only a shadow of her former self. In the days that followed Minas Anor hardened her heart, renaming herself Minas Tirith, the Tower of Guard, for she would not let what happened to her brother happen to anyone else. (to be continued)