The antecedent is in Latin very frequently (rarely in English) found in the relative clause, but more commonly in the antecedent clause.
Thus relatives serve two uses at the same time: -
1. As Nouns (or Adjectives) in their own clause: as, - eí quí Alesiae obsídébantur (B. G. vii. 77), those who were besiesled at Alesia.
2. As Connectives: as, - T. Balventius, quí superióre annó prímum pílum dúxerat (id. v. 35), Titus Balventius, who the year before had been a centurion of the first rank.
When the antecedent is in a different sentence, the relative is often equivalent to a demonstrative with a conjunction: as, - quae cum ita sint (=et cum ea ita sint), [and] since this is so.
The subordinating force did not belong to the relative originally, but was developed from an interrogative or indefinite meaning specialized by use. But the subordinating and the later connective force were acquired by quí at such au early period that the steps of the process cannot now be traced.