I have a longer post I'd like to do, but given recent events I thought I'd post a shorter verision for now.
There has been some debate in the past about the significance of Gothic Art in northern Europe and the beginning of the modern era. In the 1100s in northern France the Gothic cathedral was invented and quickly proliferated in northern and western Europe. here's a wikipedia artcile about it: https://en.wikipedia.org/wiki/Gothic_architecture#Origins_%E2%80%93_Early_Gothic_(1130%E2%80%931200)
and names and dates of earliest cathedrals: Saint-Denis Basilica 1145, Noyon Cathedral 1145, Laon Cathedra 1155, Notre Dame de Paris 1200
I know that the renaissance didn't officially start (according to Burckhardt in the 1860s) until the 1400s in Florence with the renaissance art movement there, but what was the spark that caused it?
The building of the Cathedral of Santa Maria del Fiore in Florence in 1296 and finishing in the 1400s is considered what started the art movement in Italy. Specifically the Bapistery doors by Ghiberti, early 1400s are considered to be the first great renaissance art in Europe.
I suspect what motivated the Italians was compeitition with northern Europe gothic art, and in the case of the Baptistery doors, it was the art at the entrances (Porticos-Portal) of the Gothic Cathedrals, https://en.wikipedia.org/wiki/Gothic_architecture#Portals_and_the_tympanum
I have some other arguments about the beginning of the modern era in the high middle ages including establishing the medieval universities in the 1100s, and beginning of regional merchant groups(Hanseatic, Champagne) and Merchant Banks in northern Italy in the 1100s.
Source: reddit post