Born on December 10th 1895, Alexander was the second son of William and Clara Fischer; his father was a German merchant who did not become a naturalised British citizen until nearly four years later, in March 1900. Alexander came from Streatham High School to Dulwich in 1907, joining his elder brother, Carl; they would later be joined as Alleynians by their younger brother, Hubert. He was a member of the 1st XV in each of his last two years, and in the summer of 1914 left the College, having qualified for a Tancred Scholarship at Gonville & Caius College, Cambridge.
That summer war was declared however, and two days after the declaration Alexander surrendered his place at Cambridge in order to sign up as a member of the Artists Rifles, with whom he went to France that November. A month later he was given a commission in the Devonshire Regiment, at first on a temporary basis, before later being confirmed in the position full time.
The next year he was mentioned in despatches for his services at Hill 60, but was also wounded twice. On the second occasion, after being invalided home he returned to the front with the 8th Battalion of his regiment, with whom he was serving the next year at La Corbie on the Somme, when he was killed on 12th May.