Simplify the following text for a Grade 10 native English-speaking person.
Original: Alfonso Daniel RodrÃ guez Castelao ( 30 January 1886 -- 7 January 1950 ) , most commonly known as simply Castelao , was a Galician writer in Galician language and one of the main symbols of Galician nationalism .
Simplified: Alfonso Daniel ( 30 January 1886 â `` 7 January 1950 ) , also known as Castelao , was a Spanish writer on Galician language and one of the main symbols of Galicia .