Gille Brigte, Earl of Angus
Gille Brigte of Angus is one of the earliest attested Mormaers of Angus.
He was possibly a descendant of Dubacan of Angus.
Gille Brigte is recorded as a witness to a charter dating to 1150.
He probably fathered both Adam and Gille Críst.
He was dead by 1189, when his son Adam was the Mormaer.
George Douglas, 4th Earl of Angus
George Douglas, 4th Earl of Angus, Lord Douglas, Abernethy and Jedburgh Forest( c. 1427 – 12 March 1463) was a Scottish nobleman.
He was the son of William Douglas, 2nd Earl of Angus and Margaret Hay of Yester.
Known as the Great Earl of Angus, he succeeded to the Earldom following the death of his childless brother James Douglas, 3rd Earl of Angus in 1446.
He was to become the first Red Chief of Douglas.
Louisa McDonnell, Countess of Antrim
Louisa Jane McDonnell, VA (née Grey; 15 February 1855, St. James's Palace – 2 April 1949), was the daughter of Hon.
Charles Grey (a son of the 2nd Earl Grey and Private Secretary to Prince Albert) and his wife, Caroline Eliza "née" Farquhar.
On 1 June 1875, Louisa married the 6th Earl of Antrim (thus becoming the Countess of Antrim) in the Chapel Royal at St. James's.
They had three children:
In 1890, the Countess became a Lady of the Bedchamber to Queen Victoria until the latter's death in 1901.
She was reappointed as such under Queen Alexandra in 1901 and until Edward VII's death in 1910.
The Countess of Antrim died in 1949, aged 94.
Matilda, Countess of Angus
Matilda of Angus, also known as Maud, was the daughter of Maol Choluim, Earl or Mormaer of Angus and, as his heiress, was countess of the province in her own right.
Angus McDonnell
The Honourable Angus McDonnell (7 June 1881 – 22 April 1966) was a British engineer, diplomat and Conservative Party politician.
He was the second son of William Randal McDonnell, 6th Earl of Antrim and Louisa McDonnell, Countess of Antrim.
Following education at Eton College, he briefly entered business as a merchant banker with Morgan Grenfell.
He subsequently moved to the United States of America, where he worked for
Chiswell Langhorne constructing railways in Virginia.
McDonnell became a close friend of Langhorne's daughter Nancy Astor.
With the outbreak of the First World War, he served with the railway troops reserve of the 1st Canadian Division, constructing railways behind the lines of the Western Front, rising to the rank of colonel.
He returned to the United Kingdom, where he was chosen by the Conservative Party to contest the constituency of Dartford at the 1924 general election.
He won the seat, narrowly defeating the sitting Labour Party member of parliament, John Edmund Mills.
McDonnell had little interest in parliament, and did not defend the seat in 1929, returning to his business activities.
When America entered the Second World War in 1941, McDonnell was appointed Honorary Attaché to Washington where he was able to use his personal and business contacts to assist Lord Halifax, British Ambassador to the United States.
He married Ethelwyn Sylvia Arthur Jones, the daughter of Henry Arthur Jones, on 13 December 1913.
They had no issue, and she died in 1948.
He died at 84 at his home in Tunbridge Wells, Kent, in April 1966.
Archibald Douglas, 6th Earl of Angus
Archibald Douglas, 6th Earl of Angus( c. 148922 January 1557) was a Scottish nobleman active during the reigns of James V and Mary, Queen of Scots.
He was the son of George, Master of Angus, who was killed at the Battle of Flodden, and succeeded as Earl of Angus on the death of his grandfather, Archibald.
Margaret Stewart, Countess of Angus
Margaret Stewart, Countess of Angus and Mar( died 1417) was Countess of Angus and Lady of Abernethy in her own right.
Her father was Thomas Stewart, 2nd Earl of Angus.
She was the widow of Thomas, Earl of Mar.
By an illicit affair with William Douglas, 1st Earl of Douglas, husband of the Earl of Mar's sister, she became the mother of George Douglas, 1st Earl of Angus( c. 1380- 1403), and secured a charter of her estates for her son, to whom in 1389 the title was granted by King Robert II.
William Douglas, 2nd Earl of Angus
William Douglas, 2nd Earl of Angus (24 February 1398 – October 1437) was a Scottish nobleman and soldier.
The son of George Douglas, 1st Earl of Angus and Princess Mary of Scotland, he was a grandson of King Robert III.
The story of Angus' life is interwoven with that of his uncle and King, James I of Scotland.
Angus was born about 1398 at Tantallon Castle in East Lothian.
He inherited the Earldom of Angus in 1402, following his father's death of the plague whilst in English captivity, following the Battle of Homildon Hill.
Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.
John Comyn (died 1242)
John Comyn, Earl of Angus jure uxoris, was a son of William Comyn, Lord of Badenoch later the Earl of Buchan and became the Earl of Angus, jure uxoris of his wife Matilda, heiress of Máel Coluim, Earl of Angus.
He died in 1242.

Question: Who is the maternal grandfather of Angus Mcdonnell?