ille

ille is the far demonstrative: "that one over there". It points away from the speaker, where hic points at what is close to hand and is points at nothing at all and merely refers back. That distance is not only physical. ille carries a whiff of fame and of remoteness in time, so it often amounts to "that famous one" (Alexander ille).

The declension is the pronominal pattern: nominative ille, illa, illud; accusative illum, illam, illud; genitive illius for all genders; dative illi; ablative illo, illa; plural illi, illae, illa with illorum, illarum and illis. In a hic ... ille pair the sense reverses from what English expects: hic is the latter, the thing mentioned most recently, and ille is the former. It is also the ancestor of the Romance definite article, which is where French le and Spanish el come from.