The Jacobean Period refers to the reign of King James I (of England)/VI (of Scotland). James became king of Scotland in 1567 after the execution of his mother, Mary Queen of Scots. He became king of England in 1603, after the death of Queen Elizabeth I. This was a transitional period, where the late Elizabethan styles were still mostly in play. One of the defining features of the period is extensive use of heavy embroidery picturing natural motifs, with colorful flowers and animals swirling around on the fabric.
Charles I as Prince of Wales circa 1612-13 by Robert Peake The Elder.
Richard Sackville, 3rd Earl of Dorset, by William Larkin, 1613.
Richard Sackville, 3rd Earl of Dorset, by Issac Oliver, 1616.
Anne of Denmark, by John de Critz, c. 1605
Dorothy Cary, later Viscountess Rochford, by William Larkin, 1614-1618.
Plimoth Plantation recreated an early 17th century embroidered jacket with truly spectacular results. Here's a picture of the finished project, and you can read all about the incredible endeavor here.
The Cavalier Period starts with the reign of King Charles I of England in 1625. It was a time of merriment and luxury, and the styles continued through the English Civil War. The main feature of this period is a raised waistline for both men and women. It moved to the middle of the torso, not quite as high as the under the bust empire styles we'll see in early 19th century womens wear, but not at the natural waist either. Heavy silk satins were the favored fabric.
King Charles I by Daniel Mytens, 1631.
King Charles I by Sir Anthony van Dyck, 1634.
John Belasyse by Gilbert Jackson, 1636.
Portrait of Lord John Stuart and his brother Lord Bernard Stuart (later Earl of Lichfield) by Sir Anthony van Dyck, c. 1638.
A Lady of the Spencer family by Sir Anthony van Dyck, 1633-38.
Queen Henrietta Maria of England, c. 1635.
Queen Henrietta Maria of England with Sir Jeffrey Hudson by Sir Anthony van Dyck, c. 1633.
Queen Henrietta Maria of England by Sir Anthony van Dyck, 1632-35.