1 He anointed the altar and all his vessels.—Bible
Here his refers to altar, which is a neuter noun. The quotation represents the usage of the early sixteenth century.
2 It's had it head bit off by it young—Shakespeare
Shakespeare uses his, it, and sometimes its, as possessive of it.
In Milton's poetry (seventeenth century) its occurs only three times.
3 See heaven its sparkling portals wide display—Pope
A relic of the olden time.
82. We have an interesting relic in such sentences as this from Thackeray: "One of the ways to know 'em is to watch the scared looks of the ogres' wives and children."
As shown above, the Old English objective was hem (or heom), which was often sounded with the h silent, just as we now say, "I saw 'im yesterday" when the word him is not emphatic. In spoken English, this form 'em has survived side by side with the literary them.
Use of the pronouns in personification.