Leonhard Euler, a Swiss mathematician, is widely regarded as the father of Graph Theory for his groundbreaking work on the Seven Bridges of Königsberg problem in the 18th century.

S. S. Shrikhande, an Indian mathematician, made significant contributions to Graph Theory, particularly in the area of combinatorial designs and strongly regular graphs.

A Hamiltonian Path is a path in a graph that visits every vertex exactly once and returns to the starting vertex. It is named after the Irish mathematician Sir William Rowan Hamilton.

V. R. K. Rao, an Indian mathematician, made significant contributions to the Traveling Salesman Problem, developing efficient algorithms and approximation techniques for solving this NP-hard problem.

Kruskal's Theorem states that every connected graph with at least three vertices has a spanning tree. It is named after the American mathematician Joseph Kruskal.

S. S. Shrikhande, an Indian mathematician, made significant contributions to the study of Strongly Regular Graphs, a special class of graphs with remarkable properties.

Hamilton's Conjecture states that every planar graph with at least three vertices has a Hamiltonian cycle. It is named after the Irish mathematician Sir William Rowan Hamilton.

G. S. Mahajan, an Indian mathematician, made significant contributions to Graph Coloring, developing efficient algorithms and approximation techniques for solving this NP-hard problem.

The Four Color Theorem states that every planar graph with at most four colors can be colored without any two adjacent vertices having the same color. It is one of the most famous theorems in Graph Theory.

R. C. Bose, an Indian mathematician, made significant contributions to Graph Isomorphism, developing efficient algorithms and techniques for determining whether two graphs are isomorphic.

The Graph Coloring Problem asks for the minimum number of colors needed to color the vertices of a graph such that no two adjacent vertices have the same color. It is a classic problem in Graph Theory.

V. R. K. Rao, an Indian mathematician, made significant contributions to the study of Perfect Graphs, a special class of graphs with remarkable properties.

Vizing's Theorem states that every graph with an odd number of vertices has an odd number of cycles. It is named after the Russian mathematician Vadim G. Vizing.

K. R. Parthasarathy, an Indian mathematician, made significant contributions to Ramsey Theory, a branch of Graph Theory that deals with the existence of certain subgraphs in graphs.

Turán's Problem asks for the maximum number of edges in a graph with n vertices and no cycles of length 4 or more. It is named after the Hungarian mathematician Pál Turán.