Short answers, pulled from the story.
Hermann Oldenberg was a German Indologist born in Hamburg on the 31st of October 1854. He was Professor at Kiel from 1898 and at Göttingen from 1908, and is best known for his 1881 study on Buddhism and his foundational contributions to Vedic philology.
Oldenberg's 1881 book, titled Buddha: Sein Leben, seine Lehre, seine Gemeinde (translated into English as Buddha: His Life, His Doctrine, His Order in 1882), is a study of the Buddha based on Pāli texts. It popularized Buddhism for Western readers and has remained continuously in print since its first publication.
Oldenberg translated multiple volumes for Max Müller's Sacred Books of the East series. Together with T. W. Rhys Davids he produced three volumes of Theravada Vinaya texts, and on his own he translated two volumes of Grhyasutras (volumes XXIX and XXX) and one volume of Vedic hymns to Agni (volume 46).
Oldenberg published his Prolegomena on the Rigveda in 1888, laying the groundwork for the philological study of that ancient Vedic hymn collection. It established a methodological framework for analyzing the Rigveda's structure and textual history using the tools of academic philology.
Hermann Oldenberg died on the 18th of March 1920 in Göttingen, Germany, the same city where he had held his final professorship since 1908.
In 1919, Oldenberg was elected a foreign member of the Royal Netherlands Academy of Arts and Sciences, an honor he received a year before his death.