This only feels surprising to me because in England, aristocratic houses tend to last only 100-200 years before losing their name by being subsumed into another, renaming due to politics, or vanishing in some other way.

The House of Windsor only formally dates back to 1910.

However if you trace it via the Mountbatten line, it'll rate as being as old as 1567, since it comes from a branch of the House of Hesse-Darmstadt in the Holy Roman Empire.

I think there's 3 things that might cause this:

- I am thinking that Florencian plutocratic houses simply never rename themselves. The Medici family for example continues to exist today, holding some minor titles.

- I think it also helps that Italian aristocrats were heavily involved in trade, and other mercantile professions so could continue to hold wealth and power after being deposed from statutory privilege. English aristocrats on the other hand, often only hold value in land.

- The English have historically allowed women to inherit, so family names are lost due to inheritance, enriching others with the same bloodline but different names.