William Lowndes, 68, a former Norfolk landowner, denied causing the death of his wife Carmel, a former society beauty who was once married to the Earl of Kimberley.
Mrs Lowndes, who was in her late 60s, died at the couple's luxury villa on the Costa del Sol. Mr Lowndes has been held in detention in a Seville prison since his wife was discovered lying in a pool of blood on 21 July, two years ago. The prosecution have, under Spanish law, asked for a 20- year sentence to be imposed on Mr Lowndes for manslaughter. They claim Mrs Lowndes died violently from a blow from a heavy object after an intense argument at the villa.
In 1949, the then Carmel Maguire, a renowned society beauty and daughter of the Australian boxing champion Michael Maguire, became the second wife of the Earl of Kimberley. Their marriage was dissolved three years later. The Earl, who is also the 6th Baron Wodehouse, went on to marry six times. A Conservative peer, he is a former chairman of the foreign affairs policy committee, and a former member of the House of Lords all-party defence group.
His 1949 marriage produced one son, Lord Wodehouse, who is heir to the Kimberley estate. The aristocratic family crest, showing two men wreathed about the loins, each wielding a club, has the heraldic motto, 'Strike hard'.
His son, Lord Wodehouse, 43, from Henley-on-Thames, is a research chemist, a fellow of both the British Interplanetary Society and the British Computer Society.
Lord Wodehouse and his wife were visiting his mother and stepfather on the night of the murder. A couple from a neighbouring villa in Sotogrande, near Gibraltar, also joined the Lowndeses for dinner on the night Mrs Lowndes was killed.
In his court testimony, Mr Lowndes - who moved to Spain in 1989 after selling his Thetford estate - spoke through an interpreter. He denied he killed his wife, but admitted that on the night of her death he was drunk and under strong medication. He told the court: 'I'd gone to the porch to say goodbye to the neighbours while my stepson, his wife and Carmel stayed inside. Afterwards, I sat down in an armchair on the ground floor and fell asleep. I was awakened by shouts from upstairs and I went up to my wife's bedroom where I found her dead.'
He told the court that on discovering the body of his wife he had suffered a severe nervous reaction and had jumped out the bedroom window. The fall broke both his knees. Since then he has needed crutches to walk. He entered the court on crutches flanked by two Guardia Civil police officers.
The court will have to take into account Lord Wodehouse's version of what happened. Mr Lowndes's version of the events at the villa differs from the account given by his stepson.
Lord Wodehouse, believed by the defence to be the principal beneficiary of his mother, testified that he and his wife were in their bedroom when Mr Lowndes appeared at their door and is alleged to have said: 'I think I've killed your mother.'
A doctor who arrived at the Costa del Sol villa shortly after the discovery of Mrs Lowndes's body, will give evidence in court today.