How did Notre-Dame de Paris and Laon Cathedral develop Early Gothic architecture?

Notre-Dame de Paris (begun 1163) and Laon Cathedral (begun 1165) were instrumental in developing Early Gothic architecture by building upon the structural innovations first introduced at the abbey of Saint-Denis.12

These cathedrals helped formalize the Early Gothic style through several key developments:

• Interior Elevation: They utilized a sophisticated four-story interior elevation consisting of a ground-level arcade, a tribune gallery, a triforium, and an upper clerestory. This arrangement contributed to a severe, repetitive geometry.12
• Structural Precision: Following the example of Saint-Denis, these buildings featured precise vaulting and chains of windows along the perimeter.2
• Decorative Evolution: At Laon Cathedral, architects began "binding" the interior elevation using clusters of colonettes (small, slender columns). Additionally, the elaborate figured carving common in Romanesque architecture was increasingly replaced by simplified "crocket" capitals.1
• Systematic Integration: These structures helped integrate technical elements—such as ribbed vaults and pointed arches—into a coherent, large-scale architectural language that defined the Early Gothic period.12