English is near the opposite end of the spectrum, compared to Latin, having only remnants of a previously existing case system.
Pronouns are the most vivid artifact of old English declension, having three cases: subjective, objective, and possessive. The subjective, corresponding to the Latin nominative, refers to the subject of the sentence (e.g. "I still believe that you can call out my name"); the possessive, corresponding to the Latin genitive, refers to the possessor of some other noun (e.g. "in my dearest memories"); finally, the objective, corresponding to the Latin accusative, dative, and ablative, refers to anything not a part of the other two cases (e.g. "I see you reaching out to me"). If you think about it for a minute, you'll realize that some distinct cases of the same pronoun are identical (e.g. the subjective and objective forms of "you").
For nouns, the subjective and objective cases are identical (e.g. "Kaity"). The possessive case, however, remains distinct (e.g. "Kaity's).
Interestingly, Old English used to have five cases: nominative, accusative, dative, genitive, and instrumental; as well, not only pronouns and common nouns, but also adjectives were declined. The instrumental case refers to the means by which the action of the sentence is performed. If Latin had had an instrumental case, "with burning truth" would probably have used it (but not "until the fated day", despite the fact that both use the ablative case in Latin). Interestingly, Old English lacked an ablative case; presumably the reason for this is that it relied on propositions to fill this role, as does modern English.
And for a few tangentially related bonus topics. I looked it up today, and vizzini (who is actually my boss) is right: proper nouns are declined in Latin. Also, I just had a question pop into my head: if we're evolving from simple to complex, why are languages evolving in the exact opposite way - English, Greek, etc.?