Jan Tschichold

Jan Tschichold was born in Leipzig, Germany in 1902 to Maria and Franz Tschichold. His father was a professional sign-writer, and introduced Tschichold to the world of calligraphy. From there, his passion for calligraphy and books only grew and by the age of seventeen, he began studying typography. In 1928, he published "The New Typography," which was treasured his contemporary artists and designers, but it was also displeasing to the Nazi party. After being temporarily imprisoned, Tschichold and his family relocated to Switzerland.

In 1946, Jan Tschichold moved to London where he began his work with Penguin books. There, he created guidelines and rules to be used across the board on all the books that were published by the company. Despite only working at Penguin for three years, Tschichold oversaw the redesign of more than five-hundred books. 

Tschichold was a major influence on modern typography. In his book, "The New Typography," he offered some of the first explanations on how to use differently sized and weighted fonts to convey information. After that, he wrote many typographic manuals which provided insight to many German printers and designers. Many of the principles Tschichold enforced are still in practice today.

Sources: 

https://en.wikipedia.org/wiki/Jan_Tschichold#Design

http://retinart.net/artist-profiles/jan-tschichold/

http://www.designhistory.org/Avant_Garde_pages/DieNeueType.html