Writers frequently struggle to know when a title such as king, queen, pharaoh, emperor, or the like should be capitalized and when it is more properly lowercased. SBLHS 4.3.6 includes all of these terms in a list of capitalization and spelling examples; this post reinforces the guidelines illustrated there by explaining the rationale behind them (see also CMS 8.18–32).
1. A title should be capitalized when it appears immediately before a personal name and thus effectively serves as a part of the compound name (i.e., it is part of a compound proper noun).
Pharaoh Seti I
2. When a title is used independently, not as part of a compound personal name, it is lowercased. That is, the titular word is treated as any other common noun.
3. As CMS 8.20 explains, “When a title is used in apposition before a personal name—… usually preceded by the or by a modifier—it is considered not a title but rather a descriptive phrase and is therefore lowercased.” That is, when the entire sequence consists of the + title + name, the title is lowercased because it is descriptive (common noun), not a part of a compound proper noun.
the king Saul
the queen Athaliah
the Egyptian pharaoh Seti I
the emperor Domitian
The same principle applies when the title appears after the name.
Saul the king
Athaliah the queen
Seti I the Egyptian pharaoh
Domitian the emperor
In the end, the guidelines are relatively simple: capitalize a title when it appears immediately before a name and forms a compound with it; lowercase a title in all other instances.