Complex sentence: Palmyra's wealth allowed the construction of magnificent projects and turned the city into a prosperous metropolis, with a strong army able of defeating the Sasanian Empire in 260.
Split into simpler sentences: Palmyra's wealth allowed the construction of many monumental projects that reshaped the image of the city. By the third century, Palmyra was turned into a prosperous metropolis, with a strong army able of defeating the Sassanid empire in 260.