Something that's been on my mind lately is of Operation Sealion. Perhaps there was something we weren't taught (Secondary/High School level here - 17 y/o) or I am simply forgetting;
Why did Germany not fully commit to the invasion of Great Britain, forwarding not only an aerial bombing campaign (Battle of Britain) but a naval assault, and landings of armies onto British shores?
Why only send the Luftwaffe out only to get decimated on their own, instead of backing them up with sea and land forces?
Was it that Goering convinced Hitler that the Luftwaffe could handle it alone? Surely there must have been objection to that. To throw away so much of what was critical to German conquest seems foolish, looking at it.
Thanks for the responses, everyone - new to this subreddit but very passionate for History in school. Hope to stick around a bit.
I've written a few things about this before:
What all of these answers boil down to is that Operation Sea Lion was a completely impractical operation. The Kriegsmarine had no hope of winning naval superiority in the English Channel, given that they were completely outnumbered by the Royal Navy, especially following damage sustained in Norway. The Luftwaffe's experience against ships in 1940 was not encouraging - most kills at this time were scored on ships that were stationary or moving slowly. This meant that the RN could intervene against any attempt to ship troops to the UK. The Germans also had little practical experience with amphibious operations, and very little of the specialist equipment required for it.
Because control of the air over the Channel and any landing sites is Sine Qua Non for any landing to have a chance at success or being reinforced.
Without control of the air any lumbering transports bringing more men and supplies to Britain would have been sitting ducks. The Royal Navy could have swept aside any German vessels and simply blockaded the landing beaches and let attrition and starvation do their job. All the while attempts to provide close air support or interdict enemy reinforcements would have been dicey or enormously costly.
The Kriegsmarine was simply not strong enough to force the issue either. it was frankly woefully under equipped to do the job even if air supremacy had been achieved. In summer of 1940 they could maybe put 20 warships of all sizes to see. I will ping /u/thefourthmaninaboat for the exact number but it wasn't pretty. Both Scharnhorsts had taken damage off Norway, one of the pocket BB's was operational with another in the yards, along with a single Hipper CA with another nearing completion. Added to this 3 or so operational light cruisers and a single squadron of 10 or so destroyers and that is the grand total of the German surface fleet to support any invasion. The KM had been bled badly especially in the critical numbers of destroyers in the Norway campaign, and their new ships like the Bismarck and Tirpitz would not be completed for several months.
The Nore Command for the Royal Navy had alone triple or more destroyers attached to it as the coastal command most likely to meet an invasion head one. 3 Destroyer Flotilla's were assigned with a 4th being formed in the summer of 1940. This would have been backed up by the full might of the Home Fleet's battle line and remaining carriers with HMS Rodney moved south to Rosyth as a quick reaction force. With the battlecruisers Repulse and Renown further North at Scapa Flow.
In fact the Royal Navy was comfortable enough that in June 1940 following the evacuation from Norway that many major combatants were actually sent away from Home waters to the Mediterranean both to force the issue of the French fleet, and counter the new Italian threat. While other ships like the older R class battleships did convoy work, accounting for the treat still posed should the German warships break out into the Atlantic again, which they would of course do repeatedly and most notable with the Bismarck.