Owen Glendower: An Historical Novel by John Cowper Powys was first published in America in January 1941, and in the UK in February 1942.

[1] Powys returned to Britain from the United States in 1934, with his lover Phyllis Playter, living first in Dorchester, where he began work on his novel Maiden Castle.

[2] This move to the land of his ancestors led Powys to write Owen Glendower the first of two historical novels set in this region of Wales; the other was Porius (1951).

[15] Powys finished Owen on 24 December 1939, on the hill fort of Mynydd y Gaer, above Corwen, which, according to legend, was one of the places associated with Owain Glyndŵr's last days.

The story of the rebellion of Owain Glyndŵr is seen through the eyes of his young relation, Rhisiart ab Owen of Hereford, for the first eleven chapters.

Then, in the concluding paragraph of chapter XI the point of view switches to Glendower, and he remains "the centre of attention for the rest of the book".

[20] In addition to Glyndŵr and his family, the cast of characters includes real historical figures such as Gruffydd Young and the Lollard Walter Brut.

Likewise, the historical events described in the book, such as the Battle of Pilleth and the signing of the Tripartite Indenture, are a mixture of fact and fiction; some of the incidents, such as the death of Hywel Sele,[21] are based on legend or oral tradition.

On 23 June 1400, the Eve of St John's Day, a young Oxford student, Rhisiart ab Owen, is travelling towards Wales.

Here he saves Mad Huw, who has preached that King Richard II of England is still alive, and a girl called Tegolin from being burned at the stake.

Rhisiart, Brut, Mad Huw, Master Young and a few other chosen individuals are summoned by Owen to give their opinions on the best course of action.

The following day, it is discovered that the papal messenger has taken word of the proposed rebellion to Owen's enemies, and that the Abbot at Valle Crucis is demanding hostages.

A further two years go by and Owen negotiates the Tripartite Indenture with Hotspur's father, the Earl of Northumberland, which he signs in February 1405, despite the news of a defeat for his forces in the north and the fatal injuries to his trusted "captain", Rhys Gethin.

Rhisiart, Brut, Mad Huw and Father Rheinalt are scandalized when Owen forces Tegolin to appear before the assembled troops wearing golden armour, and they prepare to oppose the prince's scheme to take her into battle with him.

The important Battle of Pwll Melyn occurs in the spring of 1405, immediately north of Usk Castle, where English forces routed their Welsh opponents, causing much loss of life, including that of Owain's brother Tudur, and Rhisiart and Tegolin were taken prisoner, along with Owen’s eldest son Griffith.

A few months later, Rhisiart and Brut are prisoners in the city of Worcester when Owen arrives at nearby Woodbury Hill at the head of a large army, having recovered many of his losses with the aid of the French.

[47] This description of the novel is supported by a scholarly introduction, or "Argument", giving historical background both to Glendower and to the period, which indicates, Powys had thoroughly researched his subject.

[63][note 3] In addition Powys makes use of literature, including the poetry of Iolo Goch, Shakespeare's Henry IV (Part I), and Lady Charlotte Guest's The Mabinogion, a collection of eleven prose stories collated from medieval Welsh manuscripts.

The Welsh mythology of this latter work, especially the Four Branches of the Mabinogi (from which Guest derived her title), is particularly important in Owen Glendower and in Powys's next novel Porius.

[68] Powys also draws on "Culhwch and Olwen" (a tale about a hero connected with King Arthur and his warriors), the "Book of Taliesin", both also found in Guest's Mabinogion, as well as mentioning Merlin, and the poet Aneirin, so that is "clear that [he] intended his ideal reader to be made perpetually aware of the ancient Welsh mythical and literary heritage".

[70] However, Glen Cavaliero suggests that "the mythogical element" is more "a kind of continuous undertow" and "for the most part it is the outward action which carries the message of the [novel]".

[78] At the beginning of the novel, Rhisiart has a "romantic vision" "of redeeming the record of an ancestor", and his relationship to Glendower and the latter's national aspiration are central to this.

He is an introspective and indecisive leader and the defeat of the Welsh arises because of Owen's refusal "to do violence to his own principles […] to his life-illusion, by unnecessary bloodshed".

[84] Cambridge poet and scholar Glen Cavaliero also notes that Glendower is "an elementalist of the kind depicted in so many of John Cowper's novels".

[90] Jeremy Hooker also emphasize this aspect of Owen Glendower, suggesting that Powys is less interested in "political and military matters" than in "consciousness, uses of the mind and will, and emotional and sexual experience".

[95] Rhisiart and Owen also resemble each other in several significant ways: "[b]oth, for example, are forced to come to terms […] with the inevitable clash between the dream possibilities of Romance and the harsh realities of life in this world".

In the New Yorker in January 1941 Clifton Fadiman suggested: However, in a 2002 novelist Margaret Drabble, in a review, commented that Powys's portrayal of Glendower is "more Welsh, more authentic, more tragic and more mythical than Shakespeare's".