Career as a national statesman
During his long career Paulet held numerous offices, which included:
High Sheriff of Hampshire 1511–12, 1518–19 and 1522–23
Joint Master of the King's Wards 1526–34 and sole Master of the King's Wards 1534–40
Member of Parliament for Hampshire 1529–36
Comptroller of the Household 1532–37
Keeper of Pamber Forest 1535/6
Treasurer of the Household 1537–38/9
Master of the King's Woods 1541
Master of the Court of Wards 1540–42
Master of the Court of Wards and Liveries 1542–54
Privy Counsellor 1542
Lord Chamberlain of the Household 1543–45
Lord Steward of the Household 1545-1549/50
Chief Justice in Eyre, South of Trent 1545–49/50
Lord President of the Council 1546–49
Joint Governor of King Edward VI
Lord Keeper of the Great Seal 1547
Keeper and Captain of St Andrew's Castle, Hamble 1547–71/2
Keeper of Alice Holt and Woolmer Forests 1548–71/2
Lord High Treasurer 1549/50–71/2
Lord High Steward for the trial of the Duke of Somerset 1551
Lord Lieutenant of Hampshire 1552, 1553 and 1559
Lieutenant of the forces in London 1558
Speaker of the House of Lords 1558 and 1566
Lord Lieutenant of Hampshire and Middlesex 1569
Joint Lord Lieutenant of London 1569
Paulet's political career began in 1529, when he was elected knight of the shire for Hampshire. In 1532, he accompanied King Henry VIII to Calais, France, and the following spring, he accompanied the Duke of Norfolk to join King Francis I of France in a proposed audience with the Pope, to discuss Henry's divorce from Catherine of Aragon. In 1536, he was granted the keepership of Pamber Forest, and on 9 March 1539 was created Baron St John. He became steward of the bishopric of Winchester, and became a close associate of Cardinal Thomas Wolsey and a friend of Thomas Cromwell. He was also Comptroller of the Royal Household, and held many other high positions.
He owned Amport House on the outskirts of the village of Amport in Hampshire.
In 1535 and 1536, he served as one of the judges for the trials of John Fisher, Sir Thomas More, and the alleged accomplices of Anne Boleyn; in 1535, he became Lord Chamberlain. He partially led the royal forces against the Pilgrimage of Grace, a rebellion that broke out in the autumn of 1536, and in 1538, he became Treasurer of the Household. In 1540, he became the master of Henry's Court of Wards and Liveries, a Knight of the Garter in 1543. In June 1543, he was one of the six commissioners of the Treaty of Greenwich, an agreement for the marriage of Mary, Queen of Scots, and Prince Edward. He was Governor of Portsmouth and Lord Steward of the Household in 1545. In 1546, he became Lord President of the Council, and in 1547, he was an executor of the will of King Henry VIII.
He continued his political manoeuvres in 1549 by supporting the Earl of Warwick against the Duke of Somerset—in reward, on 19 January 1550 he was given the Earldom of Wiltshire and Somerset's position of Lord Treasurer. In the following month Warwick took over the post of Lord President of the Council. When Warwick was created Duke of Northumberland on 11 October 1551, Paulet received the Marquessate of Winchester. Six weeks later, he served as Lord High Steward in the Duke of Somerset's trial.
It was said that Northumberland and Winchester "ruled the court" of the minor King Edward VI. Queen Mary I affirmed him in all of his positions. After her death, he remained Lord Treasurer and retained many of his other positions, and even at an advanced age (in 1559, he was over seventy years old), he showed no signs of declining—he was Speaker of the House of Lords in 1559 and 1566. He remained in good standing with the English monarchs — Queen Elizabeth I once joked, "for, by my troth, if my lord treasurer were but a young man, I could find it in my heart to have him for a husband before any man in England." Late in life, he opposed any military support of Continental Protestantism, as he feared it would cause a breach with strongly Catholic Spain.
Paulet enjoyed a remarkably long career during the Reformation. Starting out as a Catholic, he was quickly persuaded to see things Henry's way once the breach with Rome had been decided on. He was rewarded with former Church properties following the dissolution of the monasteries. Under Edward VI he became an evangelical Protestant and persecuted Roman Catholics and Henrician Conservatives alike. On the accession of the Catholic Mary he announced his reconversion and commenced persecuting his former Protestant co-religionists, even denouncing Bishop Bonner for "laxity in prosecuting the heretics." His wife also found favour with Mary. On Tuesday 21 August 1554, when Mary went into Westminster Abbey her train was carried by Elizabeth, Marchioness of Winchester and Anne of Cleves.
On Elizabeth's succession, he once again shifted his sails and became an advocate of middle-road Anglicanism. All in all, he professed five changes in religious course. Once, when asked how he managed to survive so many storms, not only unhurt, but rising all the while, Paulet answered: "By being a willow, not an oak".