U.S. President Abraham Lincoln is a famous example of a lawyer-turned-politician.
The career structure of lawyers varies widely from one country to the next.
Common law/civil law
In most common law countries, especially those with fused professions, lawyers have many options over the course of their careers. Besides private practice, they can always aspire to becoming a prosecutor, government counsel, corporate in-house counsel, administrative law judge, judge, arbitrator, law professor, or politician. There are also many non-legal jobs which legal training is good preparation for, such as corporate executive, government administrator, investment banker, entrepreneur, or journalist. In developing countries like India, a large majority of law students never actually practice, but simply use their law degree as a foundation for careers in other fields.
In most civil law countries, lawyers generally structure their legal education around their chosen specialty; the boundaries between different types of lawyers are carefully defined and hard to cross. After one earns a law degree, career mobility may be severely constrained. For example, unlike their American counterparts, it is difficult for German judges to leave the bench and become advocates in private practice. Another interesting example is France, where for much of the 20th century, all magistrates were graduates of an elite professional school for judges. Although the French magistracy has begun experimenting with the Anglo-American model of appointing judges from accomplished advocates, the few advocates who have actually joined the bench this way are looked down upon by their colleagues who have taken the traditional route to magistracy.
In a few civil law countries, such as Sweden, the legal profession is not rigorously bifurcated and everyone within it can easily change roles and arenas.