Leslie Stephen,
Dictionary of National Biography…
(1897)
“ By her Sidney had three sons—Sir Philip [q. v.] , Robert, first earl of Leicester [q. v.] , and Sir Thomas—and four daughters, two of whom died in infancy, and a third, Ambrozia, at the age of twenty, unmarried. Mary [q. v.] , the only surviving daughter, married Henry Herbert, earl of Pembroke [q. v.] , and is separately noticed. By far the ablest of the many able men that governed Ireland under Elizabeth, Sidney was throughout his career hampered by his relationship to Leicester. ”
