Born to theosophist parents who helped lead the utopian community of Halcyon, California, they grew up in a home with multiple creative influences.

The brothers showed an early interest in electricity, and after independently establishing careers in electronics and aviation they came together to invent the klystron, which became a critical component of radar, telecommunications and other microwave technologies.

In 1948 they founded Varian Associates to market the klystron and other inventions;[2] the company became the first to move into Stanford Industrial Park, the birthplace of Silicon Valley.

Both brothers were noted for their progressive political views; Russell was a lifelong supporter of the Sierra Club, Sigurd helped found the housing cooperative of Ladera, California, and Varian Associates instituted innovative employee policies that were ahead of their time.

In 1950, the Varians were awarded the John Price Wetherill Medal for the development of the klystron,[3] and both were posthumously inducted into the Silicon Valley Engineering Council Hall of Fame in 1993.

[6] John Varian became a leader of the Temple of the People at Halcyon, worked as a chiropractor and masseur,[5] wrote theosophist poetry and socialist tracts,[7] and pursued an interest in Irish myth and history.

[5] Russell was dyslexic, and in his childhood he was considered by many to be "slow", although later events would demonstrate the true extent of his intellect; Sigurd was the more outgoing of the older two siblings.

[13] Russell earned bachelor's and master's degrees in physics from Stanford University, compensating for his learning disabilities with what was described as hard work and "sheer force of will".

After a brief stint working for Southern California Edison Company stringing power lines, he took flying lessons and became a pilot, airplane mechanic,[17] and self-taught engineer.

[19] In the early 1930s, in addition to a strong interest in navigation,[15] Sigurd became concerned about the rise of Adolf Hitler in Germany and the political situation in Spain.

[10] His experience as a pilot in Central and South America made him particularly aware of the vulnerability of the Panama Canal to enemy attack, as he believed it was relatively simple to fly over a military target at night or in heavy overcast sky in the absence of a defense warning system.

"[10] Sigurd was interested in all-weather navigation systems,[3] and suggested to Russell that together they could create a radio-based technology using microwaves that could detect airplanes at night or in clouds.

[10][16] Russell agreed, and they both quit their jobs, set up their own lab at Halcyon, and began developing plans for a device that could precisely determine the location and direction of an airplane.

[17] The US and Britain were able to use this technology to create radar equipment light and compact enough to fit into aircraft,[10] which was credited with helping the Allies win the war.

[15] In 1950, the Varians were awarded the John Price Wetherill Medal of the Franklin Institute "in recognition of their foresight ... energy and technical insight in developing ... the klystron".

[3][15] Sigurd's inventions, some of which he patented, included a system of pumps, filters, and heaters for his swimming pool, as well as a high-speed drill press.

They initially created the company to commercialize the klystron[2] and develop other technologies, such as small linear accelerators to generate photons for external-beam radiation therapy.

The company began with six full-time employees: the Varian brothers, Dorothy, Myrl Stearns, Fred Salisbury, and Don Snow.

Technical and business assistance came from several members of the faculty at Stanford University, including Ginzton, Marvin Chodorow, Hansen, and Leonard Schiff.

[31][32] Francis Farquhar, an accountant and friend of Russell's from the Sierra Club, later became a director, as did Frederick Terman, Dean of Engineering at Stanford, and David Packard, of Hewlett-Packard.

[31] Russell's insistence that the company be owned by its employees and his refusal to accept outside investors led to problems in raising additional capital.

[34] In 1953, Varian Associates moved its headquarters to Palo Alto, California,[35] at Stanford Industrial Park – noted as the "spawning ground of Silicon Valley" – and was the first firm to occupy a site there.

The Varian brothers had initially been supportive of military applications for the klystron and other technologies, on the grounds that they were primarily defensive weapons, but this contract was different.

[34] Most of the founders of Varian Associates, including Russell and Sigurd, had progressive political leanings,[37] and the company "pioneered profit-sharing, stock-ownership, insurance, and retirement plans for employees long before these benefits became mandatory.

[39] Russell's wife Dorothy provided short-term loans that helped support the Varian Arabian horse breeding program in its early years.

[26] Dorothy, born in 1907, attended UC Berkeley in 1924–28, working odd jobs to pay her tuition, and graduated with a degree in economics.

[50] On October 18, 1961, Sigurd crashed his private plane into the Pacific Ocean while flying from Guadalajara to Puerto Vallarta, after losing his way in darkness.