Frederick Ulrich, Duke of Brunswick-Lüneburg

In March 1610 he visited his aunt Anne of Denmark in England, staying at St James Palace with Prince Henry, who took him to see the ship the Prince Royal being built at Woolwich.[1] He took a tour of the South West, visiting Oxford, Gloucester, Bath, and Bristol where news of the assassination of Henry IV of France reached him and ended his tour. The poet Sir David Murray, a gentleman of the household of Prince Henry, managed part of the tour, using £1,000 for expenses. He attended the masques London's Love to Prince Henry and Tethys' Festival.[2] In April he performed in a tournament "running at the ring."[3] The Prince of Wales gave him his portrait painted by Isaac Oliver. James VI and I gave him a jewel and a ring which the duke gave to Princess Elizabeth, bought for £1,900 from Peter Vanlore. After Prince Henry's death in 1612 the duke was sent a suit of gilt armour.[4]

He became ruling duke after the death of his father in 1613. In 1615, Frederick became involved in a war with the City of Brunswick, which was reluctant to recognize his overlordship.

Between 1616 and 1622, he was de facto deposed by his mother, Elizabeth, with the help of her brother, King Christian IV of Denmark, because of his alcoholism; government business was led by Anton von Streithorst, who nearly ruined the state by minting coins from cheap metals and thus causing inflation. Because of the bad situation of the state, Christian had Frederick take control of the government again. With the help of the states' nobility, he managed to regain control; the members of the Streithorst government fled the state.

Because of Frederick's indecision and weakness, Brunswick was heavily ransacked during the Thirty Years' War — both by the Catholic forces of Tilly and Pappenheim and by the Protestant forces of Christian of Denmark and Gustavus Adolphus of Sweden. The duke lost most of his territory during this time. He died after an accident in 1634.