Historically the first model of thin plate bending was developed by Lagrange, Poisson and Kirchhoff.
It is known as the Kirchhoff plate model, of simply Kirchhoff plate, in honor of the German
scientist who “closed” the mathematical formulation through the variational treatment of boundary
conditions. In the finite element literature Kirchhoff plate elements are often called C1 plate
elements because that is the continuity order nominally required for the transverse displacement
shape functions.