Maybe the other way around. Royal started in 1905 and Kirby in 1906.
Does it really matter? The better question is who marketed it better...
I've always used the Windsor Sensor xp12 and 18 since the mid 1990's I believe... Lay flat to get under beds and low hanging furniture, bag vacuum so no nasty dirt cup, can hold a conversation without shouting, on board tools, Hepa filters, use in every hospital and most hotels, last but not least it works for us..
I have a Shark at home... It was cheap..