John Beaufort, 1st Marquess of Somerset and 1st Marquess of Dorset, later only 1st Earl of Somerset, KG (1373 – 16 March 1410) was the first of the four illegitimate children of John of Gaunt, 1st Duke of Lancaster, and his mistress Katherine Swynford, later his wife. Beaufort was born in about 1371 and his surname probably reflects his father's lordship of Beaufort in Champagne, France.

The family emblem was the portcullis which is shown on the reverse of British pennies minted between 1971 and 2008. John of Gaunt had his nephew Richard II declare the Beaufort children legitimate in 1390, John of Gaunt married Katherine Swynford in January 1396. Despite being the grandchildren of Edward III, and next in the line of succession after their father's legitimate children, the Lancasters, the Beauforts, including John Beaufort, were initially barred from succession to the throne.

Early life

Early arms of John Beaufort with a bend dexter

In May to September 1390 Beaufort served in Louis II, Duke of Bourbon's crusade in North Africa. In 1394 he was in Lithuania serving with the Teutonic Knights.

In 1396, after his parents' marriage, John and his siblings were legitimated by a papal bull. Early the next year, their legitimation was recognized by an act of Parliament, and then, a few days later, John was created Earl of Somerset (10 February 1397).

That summer the new Earl was one of the noblemen who helped Richard II free himself from the power of the Lords Appellant. As a reward on 29 September he was created Marquess of Somerset and Marquess of Dorset, and sometime later that year he was made a Knight of the Garter and appointed Lieutenant of Ireland. In addition, two days before his elevation as a Marquess he married the King's niece, Margaret Holland, sister of 3rd Earl of Kent, another of the counter-appellants.

He remained in the King's favour even after his half-brother Henry Bolingbroke (later Henry IV) was banished. In February 1397 he was appointed Admiral of the Irish fleet, as well as Constable of Dover Castle and Warden of the Cinque Ports. In May his Admiralty was extended to include the northern fleet.

Later career

After Richard II was deposed by Henry Bolingbroke in 1399, the new king rescinded the titles that had been given to the counter-appellants, and thus John Beaufort became merely Earl of Somerset again. Nevertheless, he proved loyal to his half-brother's reign, serving in various military commands and on some important diplomatic missions. It was he who was given the confiscated estates of the Welsh rebel leader Owain Glyndŵr in 1400, although Beaufort could not effectively come into these estates until after 1415. In 1404 he was Constable of England.

Family

John Beaufort and his wife Margaret Beaufort, Countess of Somerset (née Holland), the daughter of Thomas Holland, 2nd Earl of Kent and Alice FitzAlan, had six children; his granddaughter Lady Margaret Beaufort married a son, (Edmund Tudor, 1st Earl of Richmond), of dowager queen Catherine of Valois by Owen Tudor — thus creating a powerful branch of the Lancastrian family which enabled the issue of that (Beaufort) marriage, Henry Tudor, ultimately to claim the throne, as Henry VII, in spite of the agreement barring the Beaufort family from the succession.

Somerset died in the Hospital of St Katharine's by the Tower. He was buried in St Michael's Chapel in Canterbury Cathedral.

His children included:

• Henry Beaufort, 2nd Earl of Somerset (1401 – 25 November 1418)
• John Beaufort, 1st Duke of Somerset (baptized 25 March 1404 – 27 May 1444)
• Joan Beaufort, Queen of Scotland (1404 – 15 July 1445) married James I, King of Scots.
• Thomas Beaufort, Count of Perche (1405 – 3 October 1431)
• Edmund Beaufort, 2nd Duke of Somerset (1406 – 22 May 1455)
• Margaret Beaufort, Countess of Devon (1409 – 1449) married Thomas de Courtenay, 13th Earl of Devon.

Arms

As a legitimated grandson of the sovereign, Beaufort bore the arms of the kingdom, differenced by a bordure gobony argent and azure.