I was a lead ship of my class, designed for a specific role, and I was named after a famous battle. I was later converted to a different role and served in a different theater of operations than originally intended. My weaponry was also modified during this conversion. What am I?

1. My class was initially designed as a very specific type of warship.
2. I was named after a significant naval battle from the first half of the 20th century.
3. I underwent a major conversion that drastically changed my capabilities and operational role.
4. I served in a different part of the world than where I was initially expected to operate.