Complex sentence: By the beginning of the 20th century singlestick play had become much neglected, the introduction of the light Italian fencing sabre having rendered it less necessary, stickplay with wooden swords as a school for the cutlass remained common in some navies.
Split into simpler sentences: By the beginning of the 20th century singlestick play had become much neglected, as the introduction of the light Italian fencing sabre having rendered unnecessary. Stickplay with wooden swords as a school for the cutlass remained common in some navies.