Complex sentence: At the beginning of May 1963, government officials invoked a rarely enforced 1958 law known as Decree Number 10 to prohibit the display of religious flags, thereby disallowing the flying of the Buddhist flag on Vesak, the birthday of Gautama Buddha.
Split into simpler sentences: At the beginning of May 1963, government officials invoked a rarely enforced 1958 law known as Decree Number 10 to prohibit the display of religious flags. In doing so, they disallowed the flying of the Buddhist flag on Vesak, the birthday of Gautama Buddha.