Agnese Battista, Portolan Chart showing British Isles
Cartographer: Olives, Jaume
Medium: Ink and pigments on vellum
This is a portolan chart of Europe by Jaume Olives, dating from 1559. This information is contained in a rubric at the head of the chart. Invented by mariners, portolan charts take their name from the Italian ‘Portolano’, meaning a written description of Catalan and Italian ports along a coastline. The first portolan Charts date from the late 13th century and represent an important change in the use of maps and charts. Until this point, most maps had held a religious significance and purpose, such as the medieval mappa mundi which was based on theological beliefs. The portolan chart contrasts with this tradition as they are based on direct observation and first hand experience and have a practical purpose. Reflecting their use by sailors they note only coastal locations, omitting most of the internal detail of the land. Place names are written at right angels to the coast, the more important ports in red ink. The lines which cover this and all other portolan charts are lines of constant bearing known as rhumb lines. These radiate from compass roses and allow the sailor to plot a course from harbour to harbour using dividers and straight edge. Here the British Isles are shown. Scotland and England are presented as separated landmasses. Typically for a chart of this date, the Bay of Cardigan is beginning to emerge on the Welsh coast, although the Lleyn Peninsular is not yet depicted. The south coast of England is the most recognisable area of the England, reflecting trading links. The Thames estuary is exaggerated in size, reflecting the importance of the London ports at this time. The depiction of Ireland includes the fabled purgatory of St Patrick, a large internal lake populated by over 300 tiny islands. The chart is decorated in the Catalan style, with figures of rulers and flags dominating.