Who commanded the French fleet that helped trap the British at Yorktown?

The Comte de Grasse commanded the French fleet that helped trap the British at Yorktown.

François Joseph Paul de Grasse led the French naval force that sailed from the West Indies to Chesapeake Bay in 1781. His arrival brought troops and helped establish the naval blockade that prevented Charles Cornwallis’s army from being reinforced or evacuated by sea.

De Grasse defeated a British relief fleet under Sir Thomas Graves at the Battle of the Chesapeake in September 1781. That naval result was essential to the Franco-American siege, because the allied armies could concentrate against Yorktown without effective British control of the bay.

De Grasse was not the commander of the French army at Yorktown. That role belonged to the Comte de Rochambeau. The Marquis de Lafayette commanded American forces in Virginia before Washington and Rochambeau moved south for the siege.