Question: When did Sir Theodore Brinckman, 1St Baronet's father die?
Answer: 12 December 1820

Theodore Henry Broadhead (3 December 1767 – 12 December 1820) was an English army officer and politician. Sir Theodore Henry Lavington Brinckman, 1st Baronet (17 January 1798 – 9 February 1880) was a British politician and baronet. Born Theodore Broadhead, he was the son of Theodore Henry Broadhead and his wife Elizabeth Macdougall, daughter of William Gordon Macdougall