Terence Rattigan’s The Winslow Boy is a superbly crafted play that manages at once to be gripping, moving and – surprisingly – extremely funny. ‘Surprisingly’ because its subject matter – the legal battle to clear the name of a 14-year-old cadet expelled from the Royal Naval College at Osborne in 1908 for stealing a five shilling postal order – hardly sounds the stuff of comedy.

That we find ourselves at the Oxford Playhouse this week savouring a wit almost Wildean in tone is testimony both to Rattigan’s enormous skill with words and to the talents of the top-quality cast assembled, under director Stephen Unwin, to interpret them.

The focus of the play is not the courtroom, of which we see not a glimpse, but the drawing room of the middle-class family engulfed in the drama. The action never strays beyond its walls. The dominant figure here (and the character who brings us so much of the laughter) is the paterfamilias Arthur Winslow, a retired bank official wonderfully portrayed by Timothy West (above). Short-tempered and irascible though he seems, it is quite apparent that beneath his crusty carapace there exists a soft-hearted and highly intelligent man with a warm regard for family and an unshakable belief in justice.

He is tolerant to a degree both of his scapegrace Oxford undergraduate elder son Dickie (Thomas Howes) and of a daughter, Catherine (Claire Cox), deeply committed to the Suffragette cause. He accepts, too, the fussing over his health of devoted wife Grace (Diane Fletcher), knowing she has his welfare at heart.

But it is in the battle to save the family name from ignominy following the expulsion of young Ronnie (Hugh Wyle) that we see him at his best. Undeterred by a legal bill he can barely afford – and in the meeting of which all members of the family must make sacrifices – he hires the services of Sir Robert Morton, the leading advocate of the day and a character closely modelled on the great Sir Edward Carson. He is impressively portrayed here by Adrian Lukis (above) who provides the high-point of the drama in his thrilling questioning of the boy.

Eventually, of course, the battle is won and a happy ending, of sorts, achieved. Rattigan has reminded us throughout, however, of the clouds of war looming over the action. It was in the very first year of this war, tragically, that George Archer-Shee, the real-life model for Ronnie, was to die in the first Battle of Ypres in 1914.

n Performances continue until Saturday. Tel: 01865 305305 (www.oxfordplayhouse.com).