Martha "Mamah" Borthwick (June 19, 1869 - August 15, 1914) is primarily noted for her relationship with Frank Lloyd Wright, which ended when she was murdered.
Borthwick earned her BA at the University of Michigan in 1892. She later worked as a librarian in Port Huron, Michigan. In 1899, Borthwick married Edwin Cheney, an electrical engineer from Oak Park, Illinois, USA. They had two children: John (1902) and Martha (1905).
Mamah met Wright's wife, Catherine, through a social club. Soon after, Edwin commissioned Wright to design them a home, now known as the Edwin H. Cheney House, and, as of 1905[update], housed an apartment below where her sister Elizabeth Bouton Borthwick lived.
In 1909, Mamah (now formally known as Martha Borthwick Cheney, although she stopped using her husband's name after they divorced in 1911) and Wright chose to leave their respective spouses and travel to Europe. Upon returning from Europe, most people in their previous social circle considered their open closeness to be rather scandalous, especially since Catherine had refused to agree to a divorce (and wouldn't until 1922). The editor of the local newspaper in Spring Green, Wisconsin condemned Wright for bringing scandal to the village; even big city Chicago papers joined in the criticism, implying Wright would soon be arrested for immorality, despite statements from the local sheriff that he couldn't prove the couple was doing anything wrong. The scandal affected Wright's career for several years. He didn't receive his next major commission, the Imperial Hotel, until 1916.
In 1911, Borthwick began translating the works of the noted Swedish feminist thinker and writer Ellen Key.
On August 15, 1914, while Wright was working in Chicago, Julian Carlton, a male servant from Barbados who had been hired several months earlier, set fire to the living quarters of Taliesin and murdered seven people with an axe as the fire burned. The dead included Mamah; her two children, John and Martha; a gardener; a draftsman named Emil Brodelle; a workman; and another workman's son. Two people survived the mayhem, one of whom helped to put out the fire that almost completely consumed the residential wing of the house. Carlton swallowed muriatic acid immediately following the attack in an attempt to kill himself. He was nearly lynched on the spot, but was taken to the Dodgeville jail. Carlton died from starvation seven weeks after the attack, despite medical attention. At the time, Wright was overseeing work on Midway Gardens in Chicago, Illinois.
In popular culture 
A detailed nonfiction account of the tragedy at Taliesin is provided in Death in a Prairie House: Frank Lloyd Wright and the Taliesin Murders by William R. Drennan.
An opera, Shining Brow, covers the story of the Cheneys and the Wrights, from when they meet in Wright's office, through the aftermath of Mamah's death. Music was composed by American composer Daron Hagen with a libretto by Paul Muldoon.