Complex sentence: He finally went up to Oxford in 1919, graduating with a first class degree in 1921 and being elected a fellow at philosophy tutor at his college two years later, getting to know CS Lewis (though Lewis described Weldon as quick to anger and cynical).
Split into simpler sentences: He finally went up to Oxford in 1919, graduating with a first class degree in 1921. Weldon was elected a fellow and philosophy tutor at his college two years later, getting to know CS Lewis (Lewis described Weldon as quick to anger and cynical).