Simplify the following text for a Grade 13 native English-speaking person.
Original: When the city became the capital of the new Mongolian People 's Republic in 1924 , its name was changed to Ulaanbaatar ( Ð # Ð '' Ð Ð Ð 1\/2 Ð Ð Ð Ñ Ð Ñ , classical script : , UlaÉ # an BaÉ # atur , literally `` red hero '' ) , in honor of Mongolia 's national hero Damdin SÃ 1\/4 khbaatar , whose warriors , shoulder-to-shoulder with the Soviet Red Army , liberated Mongolia from Roman von Ungern-Sternberg 's troops and Chinese occupation .
Simplified: Upon independence in 1911 , the city 's name changed to Niislel KhÃ 1\/4 ree ( Mongolian : Ð Ð Ð Ñ Ð '' Ñ Ð '' = `` capital '' , Ð Ò Ñ Ñ Ñ = `` camp '' ) . When the city became the capital of the new Mongolian People 's Republic in 1924 , its name was changed to Ulaanbaatar , literally `` red hero '' , in honor of Mongolia 's national hero Damdin SÃ 1\/4 khbaatar , that liberated Mongolia from Ungern von Sternberg 's troops and Chinese occupation with the Soviet Red Army .