The Russians used it against the Japanese at Nomonhon/Khalkhin (XhalXin) Gul in.... '34? And before all that, the concepts that Blitzkrieg was based on were merely the precepts of Mongol warfare--theorists including Clausewitz and most others wholeheartedly admitted that. Mobility coupled with firepower, alternately the ability to place and sustain fire in several sectors over time. The traditional, knee-jerk view is to have a big army that is everywhere. It can also be accomplished with a small, quick army.

So who "made it"? I like to look at Gustav II Adolf. He was considered the "father of modern war," even though things he did had already been done. But--ah-hah! the crux!--he put them together and succeeded with them.