Johannes Kepler was born on 27 December 1571, the first child of Catherine and Henry Kepler in Weil der Stadt in Württemberg was born. He was baptized immediately after his birth in the Catholic church. Initially, mass is no special significance in this act, but it should make later for excitement.

Johannes Kepler was a thin and sickly child from the outset. When he was about one years old, his father first went on the road because he was very restless and adventurous nature. He liked to be in the Netherlands to recruit for military service. His mother, Catherine left after the birth of her second child Henry also because of the city to nachzureisen her husband.

Thus it was that initially he also grew up with the grandparents. Four years ago he got the smallpox, which had him almost blind. This was a hard blow in his childhood, while there were the eyes of his future vocation as an astronomer, the most important senses. Here we see the irony of history: A nearly blind man laid the foundations of modern optics, and developed and improved and developed the telescope into a truly useful tool.

Another important event in his childhood took place in 1577: The boy was now six years a witness, as close to a large comet moved past the earth. At that time, comets were still interpreted as a punishment and warning of God - they were regarded as messengers of war, hunger, disease, according to the then prevailing worldview.

During this time, Kepler began attending the school, scarcely one years later, in the age of seven he attended the Latin School. But he often had to help out on the field and in his parents' restaurant so he could not attend school regularly too. Soon it was recognized that the frail, John was not suitable for heavy work and he was sent to convent school. Here he turned out to be talented, because he already was shining, the entrance exam.

He learned Latin and Greek philosophy, and rhetoric, dialectics, music, astronomy and arithmetic. The requirements were very high and very strict upbringing.
This development has led to the now seventeen-year to study at the University of Tubingen. He attended lectures on Greek, Hebrew, astronomy, physics, ethics, logic and rhetoric.

During his studies in 1590 - he was then just 19 years old - his father died. In 1591 he obtained a Masters from the philosophical, 1594, he finished his studies in Tübingen.

Before he had finished his studies, his reputation had reached such an extent that he got an offer from Graz, at the local high school teaching as a professor of mathematics at the same time take the place of the landscape mathematician Styria.
After he had accepted this offer and moved to Graz, he found enough time to turn even his private investigations in 1596 and took his first work, Mysterium Cosmo-out ".

Soon afterwards he married the twenty-three of Mühleck Barbara Mueller, who came from a very wealthy family.

Here, in Graz, Kepler was also the first time the impact of the Counter Reformation - especially since he was a Protestant - to feel. In September 1598, the situation not so much that Archduke Ferdinand dismissed all the activities of Protestants, and asked them to leave the country - otherwise faced the death penalty.

Thus it was that Kepler was now on his way to Prague. The then reigning Emperor Rudolf II, there was all very devoted to astrology and alchemy, and had worked with the astronomer Tycho Brahe observatory and a castle as a place of work and sufficient financial resources made available.
Following a request, Brahe, Kepler has now been invited by them to the aforementioned castle. What resulted was initially no cooperation, so that return Kepler even tried to Graz. As expected, he was soon expelled from there by decree and are now trying - unfortunately without success - to a chair at his former University of Tuebingen. So there was no other choice but to return to Prague, Tycho Brahe. The result was now a very fruitful cooperation between the two great astronomers, which did not last long: In October 1601 Tycho Brahe died.
Kepler has now been appointed by the Emperor Rudolf II's successor Brahe, and thus received the body of the Imperial court mathematician.
Well were finally cleared out all external obstacles, Kepler had a job now held that it was sufficiently and also the necessary financial resources to put that he is now fully able to devote himself entirely to research. This time in Prague is generally described as the most productive period in the life of Kepler. This is due not least to the patronizing benevolence of the Emperor Rudolf II. Kepler in 1606, must flee from the plague from Prague, but soon returned again. Since he himself because of his eye disease was not able to carry out a long observation of the heavens, his work relies heavily on the extensive, bequeathed to him by Tycho Brahe observational material. So he brought out in Prague several books including "Astronomiae pars Optika" (The optical part of astronomy) and "Dioptrice" (study of the refraction of light and astronomical telescope observation), in which he deals in depth with the beam in the telescope. Even here he discovered the first two famous Kepler's laws.
Also born in this time three of his twelve children. Only a few years later, his life experienced with the death of his wife Barbara at the age of 38 years due to serious illness (1611) a further deep cut.
But that's not enough: Only a year after his patron, Emperor Rudolf II died. Although he was by his brother and successor of Emperor Matthias in his post as court mathematician confirmed (1612), but Kepler was the climate for a total re-rough, mainly because Matthias is about religion not as liberal as Rudolf II - especially since he Catholic, Lutheran, Kepler was. Furthermore, although the Emperor Matthias had given him the full promised continued payment of his salary, but what Kepler did nothing because he got paid his life due to chronically empty state coffers before. So there was the emperor until his death at that time, the vast sum of nearly 12,000 guilders guilty.
So he tried again, then a professor at the University of Tubingen, but this also failed in his religious convictions.

Thus, in the same year he moved to Linz and then got a job as district mathematician. Here he was given by the City Council the task to survey the region of Upper Austria and compose a map of Austria, Styria and Carinthia. It was required of him from acting as a teacher of mathematics, philosophy and history. He was so busy with these tasks almost full, so it was only a little time for his real interests - such as astronomy.

The following year he married - now already 39 years old - the 24 year old Susanne Reutinger.
As a crucial part of his work in Linz, nor his involvement in the astronomical calendar reform as experts of the Reichstag is also relevant. Although he was a Protestant, he fought on purely objective grounds on the side of Pope Gregory XIII. implement the reform would.

The next blow was not long in coming: 1615 Kepler's mother was accused of being a witch. Although he has never thought much of his mother and his ancestors, he tried it in the drawn-out about six years and finally make 1621 with an acquittal ending process after power assistance. This has not deterred him, continue to deal with his research. So he brought out at this time a few more books and discovered the third law of Kepler's famous (T ³ / s ³ = constant).

Once in Linz, however, the print shop was burned down, in which he had put his entire financial resources for printing his works, and to him under the pressure of the Counter-Reformation, the life was too uncertain, considered him here in 1626 any more.

Then followed several turbulent years of wandering. He went first to Swabia, subsequently to Frankfurt am Main, finally arrives to Ulm and Regensburg, and returns once again for a short back to Linz. In Prague, Kepler became acquainted with the then-influential military commander Albrecht von Wallenstein. This was at that time, Duke of Mecklenburg, Friedland and Sagan. Kepler benefit from it was that Wallenstein, his life heavily in astrological predictions oriented. Wallenstein's view of astrology, but again said partial understanding of Kepler, who distinguished clearly between superstition and true astrology.

Nevertheless Wallenstein appointed him as the astrologer, as he hoped for decisive predictions must take the most Kepler was never able.
Thus, Kepler was enabled to move to Sagan in 1628 along with his family. On 8 October Kepler once traveled to Regensburg, where on 15 November at the age of nearly 59 years died.