Mathematician:Gerardus Mercator

Mathematician

Flemish geographer, cosmographer and cartographer.

Best known for the $1569$ world map based on a new projection now referred to as Mercator's projection.

Not to be confused with Nicholas Mercator.

Flemish

Born: 5 March 1512 in Rupelmonde, County of Flanders, Burgundian Netherlands (now Belgium)
Died: 2 December 1594 in Duisburg, Duchy of Cleves (now Germany)

1540: Literarum latinarum, quas italicas,cursorias que vocant, scribendarum ratio ("How to write the latin letters which they call italic or cursive")
1554: Declaratio insigniorum utilitatum quae sunt in globo terrestri : coelesti, et annulo astronomico ad invictissimum romanum imperatorem Carolum Quintum ("A description of the most important applications of the terrestrial and celestial globes and the astronomical ring. For the most invincible Roman Emperor Charles V.")
1569: Chronologia, Hoc Est Temporvm Demonstratio Exactissima, Ab Initio Mvndi, Vsqve Ad Annvm Domini M.D.LXVIII. Ex Eclipsibvs Et Observationibvs Astronomicis omnium temporum concinnata ("£A chronology, a very accurate of recorded time from the beginning of the world until AD 1568. Elaborated from astronomical observations of eclipses for all times")
1592: Evangelicae historiae quadripartita monas sive harmonia quatuor Evangelistarum ("Gospel story of fourfold unity or the harmony of the four Evangelists")

Born Geert or Gerard (de) Kremer (or Cremer)

The name Cremer is the Dutch / Flemish equivalent of the Latin Mercator (meaning Merchant).

He chose Mercator for himself around $1527$, at which time he styled himself Gerardus Mercator de Rupelmonde.

His first name Gerardus is also seen rendered as Gerhardus.