At both Eton (1901-1906) and Balliol College Oxford (1907-1910) he was a foundation scholar, and he swept the board of available academic prizes - the Reynolds and Newcastle scholarships at Eton and the Ireland, Craven, Hertford and Eldon Law scholarships while at Balliol, as well as Firsts in Honour Moderations and Greats. His contemporaries thought his pointed nose, pallid freckled complexion and red hair unattractive, but he was by common consent the intellectual star of his circle: he was President of the Annandale Society and prominent in many of the other Balliol debating and dining societies which flourished in his time. His closest friends at Balliol were all Etonians: Ronald Knox*, later his biographer; LE Jones* who also wrote about him; and a doomed group which was exuberant beyond the patience of the dons - Julian Grenfell*, Charles Alfred Lister (1887-1915), and Edward William Horner (1888-1917). Following Lister's rustication in 1908 for ridiculing the Junior Dean of Trinity College, there was an elaborate mock funeral at which Shaw-Stewart preached on the text "I wist not, brethren, that he was the high priest". 

In the autumn after Greats, he was elected a fellow of All Souls College, and he was entered as a student of the Inner Temple, but he had already accepted a job with Barings Bank. By 1913 he was a managing director. A member of the "corrupt coterie" of young aristocratic socialites which was centred on Diana Manners (Lady Diana Cooper*), he corresponded profusely and intimately with her from 1908 until a few days before his death. He was in America on bank business in 1914, but returned to England not long before war was declared. He was commissioned as a Sub-Lt in the RNVR in September 1914, joining the Hood Battalion of the RND in November. When they sailed on the Grantully Castle for the Mediterranean on 22 February 1915, he took his Herodotus as a guidebook. His mess companions included FS Kelly*, Bernard Freyberg*, and Rupert Brooke*. When they buried Brooke among the olive trees of Skyros on 23 April 1915, Shaw-Stewart commanded the firing party. After Gallipoli, where he grew a striking red beard and earned the Legion of Honour for liaison work with the French, he was attached to the French forces in Salonika through 1916, for which he was awarded the Croix de Guerre. Although appointed a staff officer (GSO.3), he badgered the War Office to be allowed to see real action, and rejoined the Hood Battalion in France in May 1917. He was killed on 30 December 1917 as its temporary commanding officer in the rank of Lt-Cdr, and was buried on 6 January 1918 in the British extension to the communal cemetery at Metz-en-Couture. 

Characterised as a "war poet" in many places, this rests on a single poem which was unknown in his lifetime, albeit a memorable one which has been printed many times since. Written in a rest period during the Dardanelles campaign, it is, like his correspondence, heavily laced with allusions to Greek epic literature.
 

I saw a man this morning      Who did not wish to die I ask, and cannot answer,      If otherwise wish I. Fair broke the day this morning      Against the Dardanelles ; The breeze blew soft, the morn's cheeks      Were cold as cold sea-shells But other shells are waiting       Across the Aegean sea, Shrapnel and high explosive,      Shells and hells for me. O hell of ships and cities,      Hell of men like me, Fatal second Helen,      Why must I follow thee ? Achilles came to Troyland      And I to Chersonese : He turned from wrath to battle,      And I from three days' peace. Was it so hard, Achilles,      So very hard to die ? Thou knewest and I know not-       So much the happier I. I will go back this morning      From Imbros over the sea ; Stand in the trench, Achilles,      Flame-capped, and shout for me.

Sources 

RA Knox, Patrick Shaw-Stewart (1920).

[BH Shaw-Stewart] Patrick Shaw Stewart 1888-1917 (privately printed 1940), with a portrait drawing [the original of which is in All Souls College].

Balliol College War Memorial Book (privately printed 1924), vol II; Shaw-Stewart's entry has a portrait photograph.

N Mosley, Julian Grenfell. His life and the times of his death 1888-1915 (1976).

L Sellers, The Hood Battalion. Royal Naval Division: Antwerp, Gallipoli, France 1914-1918 (1995).

C Page, Command in the Royal Naval Division: A military biography of Brigadier General AM Asquith DSO (1999).

J Jollife, Raymond Asquith. Life and letters (1980).

E Waugh, Ronald Knox (1959).

Lady Cynthia Asquith, Diaries 1915-18 (1968).

A Lambert, Unquiet Souls. The Indian summer of the British aristocracy (1984).

D Cooper, The rainbow comes and goes (1958).

N Jones, Rupert Brooke (1999).

LE Jones, An Edwardian youth (1956).

Lord Ribblesdale, Charles Lister: Letters and recollections with a memoir by his father (1917).

P Ziegler, Diana Cooper (1981).

P Ziegler, The sixth great power: Barings 1762-1929 (1988).

P Freyberg, Bernard Freyberg, VC. Soldier of two nations (1991).

EB Poulton, The life of Ronald Poulton (1919).

V Tree, Castles in the air. The story of my singing days (1926).

A copy of A Shropshire lad, in which Shaw-Stewart wrote his poem "I met a man this morning …….". Eton College Library.

PH Shaw-Stewart, letters to Lady Desborough [Ethel, alias 'Ettie', née Fane], Hertfordshire Archives and Local Studies, Grenfell Papers D/ERv C2491/1-91.

PH Shaw-Stewart to E Marsh, 24 May 1915, describing Rupert Brooke's last illness and death etc, Princeton University Library, Richard Halliburton Papers, ref CO247, Box 42/49.

Miscellaneous material concerning PH Shaw-Stewart, Balliol College Archives, in Shaw-Stewart's file.

Correspondence of PH Shaw-Stewart and Lady Diana Cooper [née Manners], British Library Add 70704-70720.

The Dictionary of National Biography: Shaw-Stewart has no entry but many of his associates do, including those with an asterisk* in the above notes.

J Mackenzie, The Children of the Souls (1986). This valuable source, which contains much detail concerning Shaw-Stewart, and cites letters which remain in private hands, was pointed out by Mr D. Hillage.