William was living in 1619 at the time of the Herald's Visitation to Kent, and left three sons and one daughter.

Extract of Last Will & Testament of William Cobbes; March 13, 1619:

William Cobbes of Sellendge, County Kent, Esq.

My Wife: Son James Cobbes: Only daughter Margaret Cobbes (under 18) 2nd Son; Thomas Cobbes of Chilham: Cousin, John Finche of Grovehurste, County Kent, Esq: Sister, Mrs Elizabeth Collins, Wife of William Collins, Gentleman. One Dozen Apostle Spoons to be kept as an heirloom.

Godson and Nephew, William Collins, elder son of said sister:

Exor: Son James, Cousin and old servant John Edwards:

Cousin Mr John Wright of Allington, Gentleman, and his Wife: Cap Mess known as Goldwell in the Parish of Allington, in tenancy of John Wright Road, Brambly.

George Bealings, Robert Hope, Widower, Jeckey, John Friend, George Spurling, William Chittenden and Thomas Colman: My Manor of Hody Ford, in the Parish of Sellenge: Cottage where Widow Duckett now dwells: One Demense called Southerendge, in Parish of Lympne in tenancy of Thomas Redsole: One Demense called Cobbs or Cobbs Marsh, Cratherne, Gt Fragges and Gates Leaze in Parish of Ivy Church and Newchurch, in the level of Romney Marsh, County Kent. Marsh one Demense in occupancy of Thomas Colman: One Demense know as Lamdeyes in the Parish of Allington. One Demense near Allington Fryth, in the said Parish: Wood called Landry Wood, in the said Parish: House in High Holborn in Suburbs of London. Manor of Heyton. Cousin George Smythe of Standford County Kent (No Sig)