The Bukhara Spires were circles of massive bronze spires, each etched with an intricate runic design said to be Batrachi in origin. These spires were created in the Early Dynastic period (-7975 to -6422 DR), by the Imaskari who, around this time, had mastered transdimensional magic. These permanant, two-way portals allowed the rapid transportation of whole legions over vast distances in the blink of an eye. This allowed the Imaskar Empire to rapidly expand across Eastern Faerûn. After the Silent Death (which started in -4370 DR) nearly destroyed lower Imaskar, Lord Artificer Khotan created twin Spires which connected to annother world where the people had no control over the art. During the next four centuries tens of thousands of slaves where taken from the other world. Eventually this slave population began to intermarry with the Imaskari, this gave rise to the Mulan ethnicity.