Aleksa Steiner rođen je 5. studenoga 1906. u Ljubešćici kod Varaždinskih Toplica. S deset godina odlazi na školovanje u Varaždin gdje je do 1919. pohađao klasičnu gimnaziju, a zatim 1924. maturirao u Zagrebu i 1935. diplomirao na Tehničkom fakultetu kao elektroinženjer. Tijekom studija i nakon diplomiranja usavršavao se i radio u nekoliko instituta i tvornica u Beču i Zagrebu, odakle je 1941. bio prisiljen s obitelji pobjeći pred nadirućim fašizmom. Godine 1943. odlazi u NOB gdje uspješno obavlja uglavnom tehničke poslove vezane uz radiostanicu na Mosoru i radionicu za izradu ručnih bombi i popravak oružja te hidrocentralu u Kraljevcu i tvornicu karbida u Dugom Ratu. Nakon demobilizacije 1945., kao jedan od osnivača postaje i prvim direktorom tvornice Rade Končar u Zagrebu, u kojoj je pri preuzimanju dužnosti bilo 150 radnika, a u vrijeme prelaska na novu dužnost, 1948., njihov je broj porastao na više od 2000. Slijedi preseljenje u Rijeku, gdje se posvećuje znanstvenoistraživačkom radu. Započinje kao profesor na Višoj pomorskoj školi u Rijeci (1950.–1960.). Od 1957. do 1960. na Medicinskom fakultetu u Rijeci radi kao honorarni nastavnik, a nakon habilitacije 1960. do umirovljenja (1977.) ostaje u stalnom radnom odnosu kao prvi predstojnik novoosnovanog Zavoda za fiziku. Pritom je prošao put od docenta do redovnog profesora. Uz to bio je honorarni profesor na Tehničkom fakultetu u Rijeci od 1960. do 1974. te voditelj postdiplomskog studija. Bavio se fizikom i matematikom, teorijskom elektrotehnikom i problemima regulacije, ionizacije, fermagnetizaacije te elektromagnetske indukcije u metalnim i nemetalnim vodičima. U mladosti se bavio lakom atletikom, planinarenjem, alpinizmom, skijanjem. Do kraja života ostao je pasionirani ljubitelj prirode i vrstan fotoamater., Aleksa Steiner was born in Ljubešćica near Varaždinske Toplice, Croatia on 5 November 1906. At the age of ten he left for Varaždin, where he attended the local grammar school until 1919, then moved to Zagreb, where he finished secondary school in 1924. In 1935, he graduated in electrical engineering from the Faculty of Technology. He worked in a couple of institutes and plants in Vienna and Zagreb, and then in 1941, he and his family had to flee from the fascist regime in Zagreb. In 1943, he joined the partisan movement and successfully set up a radio broadcasting station on Mt Mosor, a weapon repair workshop, hand grenade production, a hydroelectric power plant, and a carbide factory by the end of WW2. After demobilisation in 1945, with a group of people Steiner established Rade Končar, and became the factory’s first general manager. When he started Končar counted 150 workers, and by the time Steiner moved on, it already employed over 2000 people. Steiner moved to Rijeka, jumping at an opportunity to dedicate himself to scientific research. First he taught at the two-year School of Maritime Studies (1950-1960), at which time, that is, between 1957 and 1960, he already held classes at the University School of Medicine in Rijeka. From habilitation in 1960 through to retirement in 1977, he was the head of the school’s newly found Institute of Physics. Meanwhile he advanced from lecturer to full professor. He also taught at the Technical Faculty in Rijeka between 1960 and 1974, and ran a postgraduate programme. His areas of interest were physics, mathematics, theory of electrical engineering, as well as issues related to regulation, ionisation, ferromagnetism and electromagnetic field induction in metal and non-metal conductors. As a youngster, Steiner pursued athletics, trekking, alpinism and skiing. All his life he remained a passionate nature lover and a skilful amateur photographer.