In the western regions of the state situations rapidly changed, resulting in many shifts and reorganizations of units expecially cavalry units... Many of the existing Battalions were reorganized into Regiments... oversized units divided up as base fodder for other newly formed units...

Lets see if I can place this in an order to make sence...

"Giles Troop" aka Giles Volunteers mustered in Giles County Va on July 31st 1861 for one year.
Assigned as Company-D (1st) of the 8th Virginia Cavalry Regiment. Reorganized May 14th 1862 for the war. Capt William H French...

Fall of 1862 "Capt French" was authorized to raise a battalion of Cavalry.

His Cavalry company was greatly over the maximum number allowable thus it was divided on September 6th 1862 to create two cavalry companies. He kept the original, The excess number created Capt Robert Gores company. These two companies and others became the core of the new "French's Battalion" also officially designated as the 33rd Virginia Cavalry Battalion, once its organization was completed and recognized on Dec 27th 1862 with seven companies. Capt French was now Lt.Col French the battalion commander.

This organization only existed as the 33rd Va Cav Battn but a very short time. With his 7 existing companies they added 3 more companies to qualify it as a full Regiment size (10 companies). Therefore on January 28th 1863 this was again reorganized at Salem Va, and redesignated as the 17th Virginia Cavalry Regiment. French now a Colonel commanding it. French's old company now commanded by Capt James Graybill became Company-A, Capt Gores Company became Company-D of the 17th Va Cav Regt.

The 17th Va Cav Regt went on to fight at Gettysburg, Cloyds Mountain, Gen Early's 1864 Shenandoah Campaign, and saw action around Appomattox. Disbanded at Lynchburg in April 1865.

Frederick