Background
He was born the son of Sir William Tyrwhitt of Kettleby (or Kettelby), Knight Sheriff of Lincoln, and his wife, Isabel Girlington.
He was born the son of Sir William Tyrwhitt of Kettleby (or Kettelby), Knight Sheriff of Lincoln, and his wife, Isabel Girlington.
Robert, the nephew, raised and led 250 of his tenantry with the army sent against the rebel earls in 1569. He served as Justice of the Peace for Lindsey from 1547, probably until his death, and was appointed High Sheriff of Lincolnshire (1559-1560). He was joint Lord Lieutenant of Lincolnshire in 1559.
He was elected a Knight of the Shire (Member of Parliament) for Lincolnshire in 1553, 1554 and 1558.
He died in 1581 and was buried at Bigby, Lincolnshire, in a tomb of white alabaster.