Rules for DM’ing large scale battles [duplicate]

I am working on a campaign and there is a very good chance that the PC’s may find themselves involved in a large mass battle, a large siege or possibly both if things go slightly sideways in regards to there actions and success through the campaign (of course they may just as equally decide to get out of dodge if it all goes sideways but that is the joy of running a free from open campaign).

I have experience of a system for large battles from 1st edition legend of the 5 rings, a combination of the players attempting to complete heroic actions to sway the battle, combined with dice rolling the skill of the generals behind the scenes to gauge the flow of the battle. Are there any official published 5th edition rules or suggestions as to how to run these kind of large scale battles for D&D?