We often think of April 1st as more of a modern event, because it's sort of stupid and we think of our ancestors as being more serious.  

Not so.

Even the eminent biologist Charles Darwin got pranked by his shipmates on the HMS Beagle, April 1, 1832, as evidenced by his diary

While March 31st only noted a "A fine rattling breeze" the following day had him excited to make a new discovery:

All hands employed in making April fools. — at midnight almost nearly all the watch below was called up in their shirts; carpenters for a leak: quarter masters that a mast was sprung. — midshipmen to reef top-sails; All turned in to their hammocks again, some growling some laughing. — The hook was much too easily baited for me not to be caught: Sullivan cried out, "Darwin, did you ever see a Grampus: Bear a hand then". I accordingly rushed out in a transport of Enthusiasm,&was received by a roar of laughter from the whole watch. —
H/T FriendsofDarwin.com
H/T Thony Christie