Short answers, pulled from the story.
Romanesque architecture began in the year 1063 when a stone mason in Speyer carved the first groin vault for a wide nave. This architectural decision marked the birth of the style that would spread across Europe.
Archbishop Gero commissioned a life-size wooden Crucifix about 960 which remains the best-known surviving large sculptural work of Proto-Romanesque Europe. The sculpture stands as a significant example of early medieval religious art.
The largest groups of Romanesque survivors are found in areas less prosperous during subsequent periods including parts southern France rural Spain rural Portugal and rural Italy. These regions preserved unfortified secular houses palaces domestic quarters monasteries far more than churches elsewhere.
The earliest pointed vault in France appeared at the narthex of La Madeleine in Vézelay in 1130. This structure represents a key development in the evolution of ribbed vaults within the region.
Builders used double shells filled with rubble to create massive thickness because barrel vaults generally required solid walls due to outward pressure on thin structures. This method allowed them to span large spaces without relying on the engineering skills lost after the decline of Rome.